Publications of Shailesh Chandrasekharan    :chronological  alphabetical  by type listing:

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@article{fds323235,
   Author = {Hann, CT and Huffman, E and Chandrasekharan, S},
   Title = {Solution to the sign problem in a frustrated quantum
             impurity model},
   Journal = {Annals of Physics},
   Volume = {376},
   Pages = {63-75},
   Year = {2017},
   Month = {January},
   url = {http://dx.doi.org/10.1016/j.aop.2016.11.006},
   Doi = {10.1016/j.aop.2016.11.006},
   Key = {fds323235}
}

@article{fds323133,
   Author = {Huffman, E and Chandrasekharan, S},
   Title = {Solution to sign problems in models of interacting fermions
             and quantum spins.},
   Journal = {Physical review. E},
   Volume = {94},
   Number = {4-1},
   Pages = {043311},
   Year = {2016},
   Month = {October},
   Abstract = {We show that solutions to fermion sign problems that are
             found in the formulation where the path integral is expanded
             in powers of the interaction in continuous time can be
             extended to systems involving fermions interacting with
             dynamical quantum spins. While these sign problems seem
             unsolvable in the auxiliary field approach, solutions emerge
             in the world-line representation of quantum spins. Combining
             this idea with meron-cluster methods, we are able to further
             extend the class of models that are solvable. We demonstrate
             these solutions to sign problems by considering several
             examples of strongly correlated systems that contain the
             physics of semimetals, insulators, superfluidity, and
             antiferromagnetism.},
   Key = {fds323133}
}

@article{fds323134,
   Author = {Ayyar, V and Chandrasekharan, S},
   Title = {Fermion masses through four-fermion condensates},
   Journal = {The Journal of High Energy Physics},
   Volume = {2016},
   Number = {10},
   Year = {2016},
   Month = {October},
   url = {http://dx.doi.org/10.1007/JHEP10(2016)058},
   Doi = {10.1007/JHEP10(2016)058},
   Key = {fds323134}
}

@article{fds323135,
   Author = {Huffman, E and Banerjee, D and Chandrasekharan, S and Wiese,
             U-J},
   Title = {Real-time evolution of strongly coupled fermions driven by
             dissipation},
   Journal = {Annals of Physics},
   Volume = {372},
   Pages = {309-319},
   Year = {2016},
   Month = {September},
   url = {http://dx.doi.org/10.1016/j.aop.2016.05.019},
   Doi = {10.1016/j.aop.2016.05.019},
   Key = {fds323135}
}

@article{fds323136,
   Author = {Ayyar, V and Chandrasekharan, S},
   Title = {Origin of fermion masses without spontaneous symmetry
             breaking},
   Journal = {Physical Review D},
   Volume = {93},
   Number = {8},
   Year = {2016},
   Month = {April},
   url = {http://dx.doi.org/10.1103/PhysRevD.93.081701},
   Doi = {10.1103/PhysRevD.93.081701},
   Key = {fds323136}
}

@article{fds327863,
   Author = {Chandrasekharan, S},
   Title = {Fermion bags, topology and index theorems},
   Journal = {PoS - Proceedings of Science},
   Volume = {Part F128557},
   Year = {2016},
   Month = {January},
   Abstract = {© Copyright owned by the author(s). The fermion bag
             formulation helps to extend the concepts of topology and
             index theorem associated with non-Abelian gauge theories to
             simple lattice fermion field theories. Using this extension
             we can argue that fermion masses can arise either through
             the traditional mechanism where some lattice symmetry of the
             action that forbids fermion mass terms is explicitly,
             anomalously, or spontaneously broken, or through a
             non-traditional mechanism where all lattice symmetries
             continue to be preserved. We provide examples of simple
             fermion lattice field theories for each of these scenarios
             of fermion mass generation.},
   Key = {fds327863}
}

@article{fds245667,
   Author = {Ayyar, V and Chandrasekharan, S},
   Title = {Massive fermions without fermion bilinear
             condensates},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {91},
   Number = {6},
   Year = {2015},
   Month = {March},
   ISSN = {1550-7998},
   url = {http://dx.doi.org/10.1103/PhysRevD.91.065035},
   Doi = {10.1103/PhysRevD.91.065035},
   Key = {fds245667}
}

@article{fds245668,
   Author = {Zou, H and Liu, Y and Lai, C-Y and Unmuth-Yockey, J and Yang, L-P and Bazavov, A and Xie, ZY and Xiang, T and Chandrasekharan, S and Tsai,
             S-W and Meurice, Y},
   Title = {Progress towards quantum simulating the classical
             model},
   Journal = {Physical Review A - Atomic, Molecular, and Optical
             Physics},
   Volume = {90},
   Number = {6},
   Year = {2014},
   Month = {December},
   ISSN = {1050-2947},
   url = {http://dx.doi.org/10.1103/PhysRevA.90.063603},
   Doi = {10.1103/PhysRevA.90.063603},
   Key = {fds245668}
}

@article{fds303638,
   Author = {Huffman, E and Chandrasekharan, S},
   Title = {Solution to new sign problems with Hamiltonian Lattice
             Fermions},
   Journal = {PoS (LATTICE 2014) 058},
   Year = {2014},
   Month = {November},
   url = {http://arxiv.org/abs/1411.7147v2},
   Abstract = {We present a solution to the sign problem in a class of
             particle-hole symmetric Hamiltonian lattice fermion models
             on bipartite lattices using the idea of fermion bags. The
             solution remains valid when the particle-hole symmetry is
             broken through a staggered chemical potential term. This
             solution allows, for the first time, simulations of some
             massless four-fermion models with minimal fermion doubling
             and with an odd number of fermion flavors using ultra-local
             actions. One can thus study a variety of quantum phase
             transitions that have remained unexplored so far due to sign
             problems.},
   Key = {fds303638}
}

@article{fds225571,
   Author = {V. Ayyar and S. Chandrasekharan},
   Title = {Massive fermions without fermion bilinear
             condensates},
   Journal = {arXiv:1410.6474 (submitted to Phys. Rev.
             D)},
   Year = {2014},
   Month = {October},
   url = {http://arxiv.org/abs/arXiv:1410.6474},
   Abstract = {http://arxiv.org/abs/arXiv:1410.6474},
   Key = {fds225571}
}

@article{fds225570,
   Author = {E.F. Huffman and S. Chandrasekharan},
   Title = {Solution to sign problems in half-filled spin-polarized
             electronic systems},
   Journal = {Phys. Rev. (Rapid Communications)},
   Volume = {B89},
   Pages = {111101},
   Year = {2014},
   Month = {February},
   url = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.111101},
   Abstract = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.111101},
   Doi = {10.1103/PhysRevB.89.111101},
   Key = {fds225570}
}

@article{fds303637,
   Author = {Chandrasekharan, S},
   Title = {Fermion bags and a new origin for a fermion
             mass},
   Journal = {PoS - Proceedings of Science},
   Volume = {Part F130500},
   Year = {2014},
   Month = {January},
   url = {http://arxiv.org/abs/1412.3532v1},
   Abstract = {© Copyright owned by the author(s) under the terms of the
             Creative Commons Attribution-NonCommercial-ShareAlike
             Licence. The fermion bag is a powerful idea that helps to
             solve fermion lattice field theories using Monte Carlo
             methods. Some sign problems that had remained unsolved
             earlier can be solved within this framework. In this work we
             argue that the fermion bag also gives insight into a new
             mechanism of fermion mass generation, especially at strong
             couplings where fermion masses are related to the fermion
             bag size. On the other hand, chiral condensates arise due to
             zero modes in the Dirac operator within a fermion bag.
             Although in traditional four-fermion models the two
             quantities seem to be related, we show that they can be
             decoupled. While fermion bags become small at strong
             couplings, the ability of zero modes of the Dirac operator
             within fermion bags to produce a chiral condensate, can be
             suppressed by the presence of additional zero modes from
             other fermions. Thus, fermions can become massive even
             without a chiral condensate. This new mechanism of mass
             generation was discovered long ago in lattice field theory,
             but has remained unappreciated. Recent work suggests that it
             may be of interest even in continuum quantum field
             theory.},
   Key = {fds303637}
}

@article{fds225572,
   Author = {Haiyuan Zou and Yuzhi Liu and Chen-Yen Lai and J. Unmuth-Yockey and A.
             Bazavov, Z.Y. Xie and T. Xiang and S. Chandrasekharan and S. -W.
             Tsai, Y. Meurice},
   Title = {Towards quantum computing for the classical O(2)
             model},
   Journal = {Phys. Rev. A},
   Year = {2014},
   url = {http://arxiv.org/abs/arXiv:1403.5238},
   Abstract = {http://arxiv.org/abs/arXiv:1403.5238},
   Key = {fds225572}
}

@article{fds303639,
   Author = {Huffman, EF and Chandrasekharan, S},
   Title = {Solution to sign problems in half-filled spin-polarized
             electronic systems},
   Journal = {Phys. Rev. B},
   Volume = {89},
   Pages = {111101},
   Year = {2013},
   Month = {October},
   url = {http://arxiv.org/abs/1311.0034v1},
   Abstract = {We solve the sign problem in a particle-hole symmetric
             spin-polarized fermion model on bipartite lattices using the
             idea of fermion bags. The solution can be extended to a
             class of models at half filling but without particle-hole
             symmetry. Attractive Hubbard models with an odd number of
             fermion species can also be solved. The new solutions should
             allow us to study quantum phase transitions that have
             remained unexplored so far due to sign problems.},
   Doi = {10.1103/PhysRevB.89.111101},
   Key = {fds303639}
}

@article{fds303640,
   Author = {Chandrasekharan, S and Li, A},
   Title = {Quantum critical behavior in three dimensional lattice
             Gross-Neveu models},
   Volume = {88},
   Pages = {021701},
   Year = {2013},
   Month = {April},
   url = {http://arxiv.org/abs/1304.7761v1},
   Abstract = {We study quantum critical behavior in three dimensional
             lattice Gross-Neveu models containing two massless Dirac
             fermions. We focus on two models with SU(2) flavor symmetry
             and either a $Z_2$ or a U(1) chiral symmetry. Both models
             could not be studied earlier due to sign problems. We use
             the fermion bag approach which is free of sign problems and
             compute critical exponents at the phase transitions. We
             estimate $\nu = 0.83(1)$, $\eta = 0.62(1)$, $\eta_\psi =
             0.38(1)$ in the $Z_2$ and $\nu = 0.849(8)$, $\eta =
             0.633(8)$, $\eta_\psi = 0.373(3)$ in the U(1)
             model.},
   Doi = {10.1103/PhysRevD.88.021701},
   Key = {fds303640}
}

@article{fds303641,
   Author = {Chandrasekharan, S},
   Title = {Fermion Bag Approach to Fermion Sign Problems},
   Volume = {49},
   Pages = {90},
   Year = {2013},
   Month = {April},
   url = {http://arxiv.org/abs/1304.4900v1},
   Abstract = {The fermion bag approach is a new method to tackle fermion
             sign problems in lattice field theories. Using this approach
             it is possible to solve a class of sign problems that seem
             unsolvable by traditional methods. The new solutions emerge
             when partition functions are written in terms of fermion
             bags and bosonic worldlines. In these new variables it is
             possible to identify hidden pairing mechanisms which lead to
             the solutions. The new solutions allow us for the first time
             to use Monte Carlo methods to solve a variety of interesting
             lattice field theories, thus creating new opportunities for
             understanding strongly correlated fermion
             systems.},
   Doi = {10.1140/epja/i2013-13090-y},
   Key = {fds303641}
}

@article{fds323137,
   Author = {Chandrasekharan, S},
   Title = {Quantum critical behavior with massless staggered fermions
             in three dimensions},
   Journal = {PoS - Proceedings of Science},
   Volume = {29-July-2013},
   Pages = {049},
   Year = {2013},
   Month = {January},
   url = {http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=187},
   Abstract = {We report on studies of quantum critical behavior in three
             dimensional lattice Gross-Neveu models with one flavor of
             staggered fermions. We focus on two models, one with
             SU(2)×Z2 symmetry and the other with an SU(2)×U(1)
             symmetry. Both these models could not be studied earlier
             with conventional Monte Carlo methods due to sign problems.
             However, the fermion bag approach is free of sign problems
             for these models and allows us to compute the critical
             exponents at the quantum phase transition that separates the
             massless fermion phase at small couplings and the massive
             fermion phase at large couplings. Our results help resolve
             some old puzzles in the field.},
   Key = {fds323137}
}

@article{PosLattice2012,
   Author = {Chandrasekharan Shailesh},
   Title = {Fermion Bag Solutions to Sign Problems},
   Journal = {Proceedings of Science},
   Volume = {Lattice2012},
   Pages = {224},
   Year = {2012},
   Month = {December},
   Key = {PosLattice2012}
}

@article{PhysRevLett.108.140404,
   Author = {Chandrasekharan, S and Li, A},
   Title = {Fermion bags, duality, and the three dimensional massless
             lattice thirring model.},
   Journal = {Physical Review Letters},
   Volume = {108},
   Number = {14},
   Pages = {140404},
   Publisher = {American Physical Society},
   Year = {2012},
   Month = {April},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/22540775},
   Abstract = {The recently proposed fermion-bag approach is a powerful
             technique to solve some four-fermion lattice field theories.
             Because of the existence of a duality between strong and
             weak couplings, the approach leads to efficient Monte Carlo
             algorithms in both these limits. The new method allows us
             for the first time to accurately compute quantities close to
             the quantum critical point in the three dimensional lattice
             Thirring model with massless fermions on large lattices. The
             critical exponents at the quantum critical point are found
             to be ν=0.85(1), η=0.65(1), and η(ψ)=0.37(1).},
   Doi = {10.1103/PhysRevLett.108.140404},
   Key = {PhysRevLett.108.140404}
}

@article{PhysRevD.85.091502,
   Author = {Chandrasekharan, S and Li, A},
   Title = {Fermion bag solutions to some sign problems in four-fermion
             field theories},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {85},
   Number = {9},
   Pages = {091502},
   Publisher = {American Physical Society},
   Year = {2012},
   ISSN = {1550-7998},
   url = {http://link.aps.org/doi/10.1103/PhysRevD.85.091502},
   Abstract = {Lattice four-fermion models containing N flavors of
             staggered fermions, which are invariant under Z 2 and U(1)
             chiral symmetries, are known to suffer from sign problems
             when formulated using the auxiliary field approach. Although
             these problems have been ignored in previous studies, they
             can be severe. Here we show that the sign problems disappear
             when the models are formulated in the fermion bag approach,
             allowing us to solve them rigorously for the first time. ©
             2012 American Physical Society.},
   Doi = {10.1103/PhysRevD.85.091502},
   Key = {PhysRevD.85.091502}
}

@article{PhysRevD.86.021701,
   Author = {Chandrasekharan, S},
   Title = {Solutions to sign problems in lattice Yukawa
             models},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {86},
   Number = {2},
   Pages = {021701},
   Publisher = {American Physical Society},
   Year = {2012},
   ISSN = {1550-7998},
   url = {http://link.aps.org/doi/10.1103/PhysRevD.86.021701},
   Abstract = {We prove that sign problems in the traditional approach to
             some lattice Yukawa models can be completely solved when
             fermions are formulated using fermion bags and bosons are
             formulated in the worldline representation. We prove this
             within the context of two examples of three-dimensional
             models, symmetric under U L(1)×U R(1)×Z 2(parity)
             transformations, one involving staggered fermions and the
             other involving Wilson fermions. We argue that these models
             have interesting quantum phase transitions that can now be
             studied using Monte Carlo methods. © 2012 American Physical
             Society.},
   Doi = {10.1103/PhysRevD.86.021701},
   Key = {PhysRevD.86.021701}
}

@article{fds303646,
   Author = {Chandrasekharan, S and Li, A},
   Title = {The generalized fermion-bag approach},
   Volume = {Lattice 2011},
   Pages = {058},
   Year = {2011},
   Month = {November},
   url = {http://arxiv.org/abs/1111.5276v1},
   Abstract = {We present a new approach to some four-fermion lattice field
             theories which we call the generalized fermion bag approach.
             The basic idea is to identify unpaired fermionic degrees of
             freedom that cause sign problems and collect them in a bag.
             Paired fermions usually act like bosons and do not lead to
             sign problems. A resummation of all unpaired fermion degrees
             of freedom inside the bag is sufficient to solve the fermion
             sign problem in a variety of interesting cases. Using a
             concept of duality we then argue that the size of the
             fermion bags is small both at strong and weak couplings.
             This allows us to construct efficient algorithms in both
             these limits. Using the fermion bag approach, we study the
             quantum phase transition of the 3D massless lattice
             Thirrring model which is of interest in the context of
             Graphene. Using our method we are able to solve the model on
             lattices as large as $40^3$ with moderate computational
             resources. We obtain the precise location of the quantum
             critical point and the values of the critical exponents
             through this study.},
   Key = {fds303646}
}

@article{fds303643,
   Author = {Chandrasekharan, S and Wiese, U-J},
   Title = {Partition Functions of Strongly Correlated Electron Systems
             as "Fermionants"},
   Year = {2011},
   Month = {August},
   url = {http://arxiv.org/abs/1108.2461v1},
   Abstract = {We introduce a new mathematical object, the "fermionant"
             ${\mathrm{Ferm}}_N(G)$, of type $N$ of an $n \times n$
             matrix $G$. It represents certain $n$-point functions
             involving $N$ species of free fermions. When N=1, the
             fermionant reduces to the determinant. The partition
             function of the repulsive Hubbard model, of geometrically
             frustrated quantum antiferromagnets, and of Kondo lattice
             models can be expressed as fermionants of type N=2, which
             naturally incorporates infinite on-site repulsion. A
             computation of the fermionant in polynomial time would solve
             many interesting fermion sign problems.},
   Key = {fds303643}
}

@article{fds212507,
   Author = {S. Chandrasekharan and U.-J. Wiese},
   Title = {Partition Functions of Strongly Correlated Electron Systems
             as 'Fermionants'.},
   Journal = {arXiv:1108.2461},
   Year = {2011},
   Month = {July},
   url = {http://arxiv.org/abs/arXiv:1108.2461},
   Abstract = {We introduce a new mathematical object, the "fermionant"
             ${\mathrm{Ferm}}_N(G)$, of type $N$ of an $n \times n$
             matrix $G$. It represents certain $n$-point functions
             involving $N$ species of free fermions. When N=1, the
             fermionant reduces to the determinant. The partition
             function of the repulsive Hubbard model, of geometrically
             frustrated quantum antiferromagnets, and of Kondo lattice
             models can be expressed as fermionants of type N=2, which
             naturally incorporates infinite on-site repulsion. A
             computation of the fermionant in polynomial time would solve
             many interesting fermion sign problems.},
   Key = {fds212507}
}

@article{fds245681,
   Author = {Chandrasekharan, S and Li, A},
   Title = {Fermion bag approach to the sign problem in strongly coupled
             lattice QED with Wilson fermions},
   Journal = {Journal of High Energy Physics},
   Volume = {2011},
   Number = {1},
   Year = {2011},
   ISSN = {1126-6708},
   url = {http://www.springerlink.com/content/e051x42j2xn1x087/},
   Abstract = {We explore the sign problem in strongly coupled lattice QED
             with one flavor of Wilson fermions in four dimensions using
             the fermion bag formulation. We construct rules to compute
             the weight of a fermion bag and show that even though the
             fermions are confined into bosons, fermion bags with
             negative weights do exist. By classifying fermion bags as
             either simple or complex, we find numerical evidence that
             large complex bags with positive and negative weights come
             with equal probabilities. On the other hand simple bags have
             a large probability of having a positive weight. In analogy
             with the meron cluster approach, we suggest that eliminating
             the complex bags from the partition function should
             alleviate the sign problem while capturing the important
             physics. We also find a modified model containing only
             simple bags which does not suffer from any sign problem and
             argue that it contains a parity breaking phase transition
             similar to the original model. We also prove that when the
             hopping parameter is strictly infinite all fermion bags are
             non-negative. © SISSA 2011.},
   Doi = {10.1007/JHEP01(2011)018},
   Key = {fds245681}
}

@article{fds245683,
   Author = {Liu, DE and Chandrasekharan, S and Baranger, HU},
   Title = {Quantum phase transition and emergent symmetry in a
             quadruple quantum dot system.},
   Journal = {Physical Review Letters},
   Volume = {105},
   Number = {25},
   Pages = {256801},
   Year = {2010},
   Month = {December},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/21231607},
   Abstract = {We propose a system of four quantum dots designed to study
             the competition between three types of interactions:
             Heisenberg, Kondo, and Ising. We find a rich phase diagram
             containing two sharp features: a quantum phase transition
             (QPT) between charge-ordered and charge-liquid phases and a
             dramatic resonance in the charge liquid visible in the
             conductance. The QPT is of the Kosterlitz-Thouless type with
             a discontinuous jump in the conductance at the transition.
             We connect the resonance phenomenon with the degeneracy of
             three levels in the isolated quadruple dot and argue that
             this leads to a Kondo-like emergent symmetry from left-right
             Z2 to U(1).},
   Doi = {10.1103/PhysRevLett.105.256801},
   Key = {fds245683}
}

@article{fds245682,
   Author = {Chandrasekharan, S and Li, A},
   Title = {Anomaly and a QCD-like phase diagram with massive bosonic
             baryons},
   Journal = {Journal of High Energy Physics},
   Volume = {2010},
   Number = {12},
   Year = {2010},
   ISSN = {1126-6708},
   url = {http://www.springerlink.com/content/f44x269565536614/},
   Abstract = {We study a strongly coupled Z 2 lattice gauge theory with
             two flavors of quarks, invariant under an exact
             SU(2)×SU(2)×U A(1)×U B(1) symmetry which is the same as
             in QCD with two flavors of quarks without an anomaly. The
             model also contains a coupling that can be used to break the
             U A(1) symmetry and thus mimic the QCD anomaly. At low
             temperatures T and small baryon chemical potential μ B the
             model contains massless pions and massive bosonic baryons
             similar to QCD with an even number of colors. In this work
             we study the T - μ B phase diagram of the model and show
             that it contains three phases: (1) A chirally broken phase
             at low T and μ B, (2) a chirally symmetric baryon
             superfluid phase at low T and high μ B, and (3) a symmetric
             phase at high T. We find that the nature of the finite
             temperature chiral phase transition and in particular the
             location of the tricritical point that seperates the first
             order line from the second order line is affected
             significantly by the anomaly. © 2010 SISSA.},
   Doi = {10.1007/JHEP12(2010)021},
   Key = {fds245682}
}

@article{fds245684,
   Author = {Liu, DE and Chandrasekharan, S and Baranger, HU},
   Title = {Conductance of quantum impurity models from quantum monte
             carlo},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {82},
   Number = {16},
   Pages = {165447},
   Year = {2010},
   ISSN = {1098-0121},
   url = {http://hdl.handle.net/10161/4258 Duke open
             access},
   Abstract = {The conductance of two Anderson impurity models, one with
             twofold and another with fourfold degeneracy, representing
             two types of quantum dots, is calculated using a world-line
             quantum Monte Carlo (QMC) method. Extrapolation of the
             imaginary time QMC data to zero frequency yields the linear
             conductance, which is then compared to numerical
             renormalization-group results in order to assess its
             accuracy. We find that the method gives excellent results at
             low temperature (T TK) throughout the mixed-valence and
             Kondo regimes but it is unreliable for higher temperature.
             © 2010 The American Physical Society.},
   Doi = {10.1103/PhysRevB.82.165447},
   Key = {fds245684}
}

@article{fds245685,
   Author = {Chandrasekharan, S},
   Title = {Fermion bag approach to lattice field theories},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {82},
   Number = {2},
   Pages = {025007},
   Year = {2010},
   ISSN = {1550-7998},
   url = {http://hdl.handle.net/10161/4276 Duke open
             access},
   Abstract = {We propose a new approach to the fermion sign problem in
             systems where there is a coupling U such that when it is
             infinite the fermions are paired into bosons, and there is
             no fermion permutation sign to worry about. We argue that as
             U becomes finite, fermions are liberated but are naturally
             confined to regions which we refer to as fermion bags. The
             fermion sign problem is then confined to these bags and may
             be solved using the determinantal trick. In the parameter
             regime where the fermion bags are small and their typical
             size does not grow with the system size, construction of
             Monte Carlo methods that are far more efficient than
             conventional algorithms should be possible. In the region
             where the fermion bags grow with system size, the fermion
             bag approach continues to provide an alternative approach to
             the problem but may lose its main advantage in terms of
             efficiency. The fermion bag approach also provides new
             insights and solutions to sign problems. A natural solution
             to the "silver blaze problem" also emerges. Using the
             three-dimensional massless lattice Thirring model as an
             example, we introduce the fermion bag approach and
             demonstrate some of these features. We compute the critical
             exponents at the quantum phase transition and find
             ν=0.87(2) and η=0.62(2). © 2010 The American Physical
             Society.},
   Doi = {10.1103/PhysRevD.82.025007},
   Key = {fds245685}
}

@article{fds245686,
   Author = {Banerjee, D and Chandrasekharan, S},
   Title = {Finite size effects in the presence of a chemical potential:
             A study in the classical nonlinear O(2) sigma
             model},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {81},
   Number = {12},
   Pages = {125007},
   Year = {2010},
   ISSN = {1550-7998},
   url = {http://hdl.handle.net/10161/4275 Duke open
             access},
   Abstract = {In the presence of a chemical potential, the physics of
             level crossings leads to singularities at zero temperature,
             even when the spatial volume is finite. These singularities
             are smoothed out at a finite temperature but leave behind
             nontrivial finite size effects which must be understood in
             order to extract thermodynamic quantities using Monte Carlo
             methods, particularly close to critical points. We
             illustrate some of these issues using the classical
             nonlinear O(2) sigma model with a coupling β and chemical
             potential μ on a 2+1-dimensional Euclidean lattice. In the
             conventional formulation this model suffers from a sign
             problem at nonzero chemical potential and hence cannot be
             studied with the Wolff cluster algorithm. However, when
             formulated in terms of the worldline of particles, the sign
             problem is absent, and the model can be studied efficiently
             with the "worm algorithm." Using this method we study the
             finite size effects that arise due to the chemical potential
             and develop an effective quantum mechanical approach to
             capture the effects. As a side result we obtain energy
             levels of up to four particles as a function of the box size
             and uncover a part of the phase diagram in the (β,μ)
             plane. © 2010 The American Physical Society.},
   Doi = {10.1103/PhysRevD.81.125007},
   Key = {fds245686}
}

@article{fds184647,
   Author = {D. Podolski and S. Chandrasekharan and A.Vishwanath},
   Title = {Phase Transitions of S=1 Spinor Condensates in an optical
             lattice},
   Journal = {Physical Review B},
   Volume = {80},
   Pages = {214513},
   Year = {2009},
   url = {http://prb.aps.org/abstract/PRB/v80/i21/e214513},
   Abstract = {We study the phase diagram of spin-one polar condensates in
             a two dimensional optical lattice with magnetic anisotropy.
             We show that the topological binding of vorticity to nematic
             disclinations allows for a rich variety of phase
             transitions. These include Kosterlitz-Thouless-like
             transitions with a superfluid stiffness jump that can be
             experimentally tuned to take a continuous set of values, and
             a new cascaded Kosterlitz-Thouless" transition,
             characterized by two divergent length scales. For higher
             boson spin S, the thermal phase transitions are strongly
             affected by the parity of S.},
   Key = {fds184647}
}

@article{Podolsky:2007x,
   Author = {Podolsky, D and Chandrasekharan, S and Vishwanath,
             A},
   Title = {Phase transitions of S=1 spinor condensates in an optical
             lattice},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {80},
   Number = {21},
   Year = {2009},
   ISSN = {1098-0121},
   url = {http://hdl.handle.net/10161/3298 Duke open
             access},
   Abstract = {We study the phase diagram of spin-one polar condensates in
             a two-dimensional optical lattice with magnetic anisotropy.
             We show that the topological binding of vorticity to nematic
             disclinations allows for a rich variety of phase
             transitions. These include Kosterlitz-Thouless-like
             transitions with a superfluid stiffness jump that can be
             experimentally tuned to take a continuous set of values, and
             a cascaded Kosterlitz-Thouless transition, characterized by
             two divergent length scales. For higher integer spin bosons
             S, the thermal phase transition out of the planar polar
             phase is strongly affected by the parity of S. © 2009 The
             American Physical Society.},
   Doi = {10.1103/PhysRevB.80.214513},
   Key = {Podolsky:2007x}
}

@article{fds245704,
   Author = {Kaul, RK and Ullmo, D and Zaránd, G and Chandrasekharan, S and Baranger, HU},
   Title = {Ground state and excitations of quantum dots with magnetic
             impurities},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {80},
   Number = {3},
   Pages = {035318},
   Year = {2009},
   ISSN = {1098-0121},
   url = {http://link.aps.org/abstract/PRB/v80/e035318},
   Abstract = {We consider an "impurity" with a spin degree of freedom
             coupled to a finite reservoir of noninteracting electrons, a
             system which may be realized by either a true impurity in a
             metallic nanoparticle or a small quantum dot coupled to a
             large one. We show how the physics of such a spin impurity
             is revealed in the many-body spectrum of the entire
             finite-size system; in particular, the evolution of the
             spectrum with the strength of the impurity-reservoir
             coupling reflects the fundamental many-body correlations
             present. Explicit calculation in the strong- and the
             weak-coupling limits shows that the spectrum and its
             evolution are sensitive to the nature of the impurity and
             the parity of electrons in the reservoir. The effect of the
             finite-size spectrum on two experimental observables is
             considered. First, we propose an experimental setup in which
             the spectrum may be conveniently measured using tunneling
             spectroscopy. A rate equation calculation of the
             differential conductance suggests how the many-body spectral
             features may be observed. Second, the finite-temperature
             magnetic susceptibility is presented, both the impurity and
             the local susceptibilities. Extensive quantum Monte Carlo
             calculations show that the local susceptibility deviates
             from its bulk scaling form. Nevertheless, for special
             assumptions about the reservoir-the "clean Kondo box"
             model-we demonstrate that finite-size scaling is recovered.
             Explicit numerical evaluations of these scaling functions
             are given, both for even and odd parities and for the
             canonical and the grand-canonical ensembles. © 2009 The
             American Physical Society.},
   Doi = {10.1103/PhysRevB.80.035318},
   Key = {fds245704}
}

@article{Cecile:2008gs,
   Author = {Cecile, DJ and Chandrasekharan, S},
   Title = {Sigma-resonance and convergence of chiral perturbation
             theory},
   Journal = {PoS LATTICE},
   Volume = {2008},
   Pages = {071},
   Year = {2008},
   Month = {October},
   url = {http://arxiv.org/abs/0810.2423v1},
   Abstract = {The dimensionless parameter $\xi' = M^2/(16 \pi^2 F^2)$,
             where $F$ is the pion decay constant in the chiral limit and
             $M$ is the pion mass at leading order in the quark mass, is
             expected to control the convergence of chiral perturbation
             theory applicable to QCD. Here we demonstrate that a
             strongly coupled lattice gauge theory model with the same
             symmetries as two-flavor QCD but with a much lighter
             $\sigma$-resonance is different. Our model allows us to
             study efficiently the convergence of chiral perturbation
             theory as a function of $\xi'$. We first confirm that the
             leading low energy constants appearing in the chiral
             Lagrangian are the same when calculated from the
             $\epsilon$-regime and the $p$-regime. However, $\xi'
             \lesssim 0.002$ is necessary before 1-loop chiral
             perturbation theory predicts the data within 1%. However,
             for $\xi' > 0.0035$ the data begin to deviate qualitatively
             from 1-loop chiral perturbation theory predictions. We argue
             that this qualitative change is due to the presence of a
             light $\sigma$-resonance in our model. Our findings may be
             useful for lattice QCD studies.},
   Key = {Cecile:2008gs}
}

@article{Chandrasekharan:2008gp,
   Author = {Chandrasekharan, S},
   Title = {A new computational approach to lattice quantum field
             theories},
   Journal = {PoS LATTICE},
   Volume = {2008},
   Pages = {003},
   Year = {2008},
   Month = {October},
   url = {http://arxiv.org/abs/0810.2419v1},
   Abstract = {Developments in algorithms over the past decade suggest that
             there is a new computational approach to a class of quantum
             field theories. This approach is based on rewriting the
             partition function in a representation similar to the
             world-line representation and hence we shall call it the
             "WL-approach". This approach is likely to be more powerful
             than the conventional approach in some regions of parameter
             space, especially in the presence of chemical potentials or
             massless fermions. While world-line representations are
             natural in the Hamiltonian formulation, they can also be
             constructed directly in Euclidean space. We first describe
             the approach and its advantages by considering the classical
             XY model in the presence of a chemical potential. We then
             argue that, $CP^{N-1}$ models, models of pions on the
             lattice and the lattice massless Thirring model, can all be
             formulated and solved using the WL-approach. In particular,
             we discover that the WL-approach to the Thirring model leads
             to a novel determinantal Monte-Carlo algorithm which we call
             the "dynamical-bag" algorithm. Finally, we argue that a
             simple extension of the WL-approach to gauge theories leads
             to a world-sheet, "WS-approach", in Abelian Lattice Gauge
             theory.},
   Key = {Chandrasekharan:2008gp}
}

@article{fds245669,
   Author = {Jiang, F-J and Nyfeler, M and Chandrasekharan, S and Wiese,
             U-J},
   Title = {From an antiferromagnet to a valence bond solid: evidence
             for a first-order phase transition},
   Journal = {Journal of statistical mechanics (Online)},
   Year = {2008},
   Month = {February},
   ISSN = {1742-5468},
   url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000254376400010&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
   Doi = {10.1088/1742-5468/2008/02/P02009},
   Key = {fds245669}
}

@article{Cecile:2007dv,
   Author = {Cecile, D. J. and Chandrasekharan, Shailesh},
   Title = {Modeling pion physics in the $\epsilon$-regime of two-
             flavor QCD using strong coupling lattice
             QED},
   Journal = {Phys. Rev.},
   Volume = {D77},
   Pages = {014506},
   Year = {2008},
   url = {http://arxiv.org/pdf/arXiv:0708.0558 [hep-lat]},
   Abstract = {http://arxiv.org/abs/arXiv:0708.0558 [hep-lat]},
   Key = {Cecile:2007dv}
}

@article{Chandrasekharan:2008gp,
   Author = {Chandrasekharan, Shailesh},
   Title = {A new computational approach to lattice quantum field
             theories},
   Journal = {PoS},
   Volume = {LATTICE2008},
   Pages = {003},
   Year = {2008},
   url = {http://arxiv.org/pdf/0810.2419},
   Abstract = {http://arxiv.org/abs/0810.2419},
   Key = {Chandrasekharan:2008gp}
}

@article{Chandrasekharan:2007sch,
   Author = {Jiang, F.-J. and Nyfeler, M. and Chandrasekharan, S. and Wiese, U. -J.},
   Title = {From an Antiferromagnet to a Valence Bond Solid: Evidence
             for a First Order Phase Transition},
   Journal = {J. of Stat. Mech},
   Volume = {P02009},
   Year = {2008},
   Key = {Chandrasekharan:2007sch}
}

@article{chandrasekharan:077901,
   Author = {S. Chandrasekharan and F.-J. Jiang and M. Pepe and U.-J.
             Wiese},
   Title = {Rotor spectra, berry phases, and monopole fields: From
             antiferromagnets to QCD},
   Journal = {Physical Review D (Particles and Fields)},
   Volume = {78},
   Number = {7},
   Pages = {077901},
   Publisher = {APS},
   Year = {2008},
   url = {http://link.aps.org/abstract/PRD/v78/e077901},
   Key = {chandrasekharan:077901}
}

@article{Cecile:2008kp,
   Author = {Cecile, D. J. and Chandrasekharan, Shailesh},
   Title = {Role of the $\sigma$-resonance in determining the
             convergence of chiral perturbation theory},
   Journal = {Phys. Rev.},
   Volume = {D77},
   Pages = {091501},
   Year = {2008},
   url = {http://arxiv.org/pdf/0801.3823},
   Abstract = {http://arxiv.org/abs/0801.3823},
   Key = {Cecile:2008kp}
}

@article{Cecile:2008nb,
   Author = {Cecile, D. J. and Chandrasekharan, Shailesh},
   Title = {Absence of vortex condensation in a two dimensional
             fermionic XY model},
   Journal = {Phys. Rev.},
   Volume = {D77},
   Pages = {054502},
   Year = {2008},
   url = {http://arxiv.org/pdf/arXiv:0801.1857 [hep-lat]},
   Abstract = {http://arxiv.org/abs/arXiv:0801.1857 [hep-lat]},
   Key = {Cecile:2008nb}
}

@article{fds245705,
   Author = {Cecile, DJ and Chandrasekharan, S},
   Title = {Role of the σ resonance in determining the convergence of
             chiral perturbation theory},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {77},
   Number = {9},
   Pages = {091501},
   Year = {2008},
   ISSN = {1550-7998},
   url = {http://link.aps.org/doi/10.1103/PhysRevD.77.091501},
   Abstract = {The dimensionless parameter ξ=Mπ2/(16π2Fπ2), where Fπ
             is the pion decay constant and Mπ is the pion mass, is
             expected to control the convergence of chiral perturbation
             theory applicable to QCD. Here we demonstrate that a
             strongly coupled lattice gauge theory model with the same
             symmetries as two-flavor QCD but with a much lighter
             σ-resonance is different. We first confirm that the leading
             low-energy constants appearing in the chiral Lagrangian are
             the same when calculated from the p-regime and the -regime
             as expected. However, ξ 0.002 is necessary before 1-loop
             chiral perturbation theory predicts the data within 1%. For
             ξ>0.0035 the data begin to deviate dramatically from
             1-loop chiral perturbation theory predictions. We argue that
             this qualitative change is due to the presence of a light
             σ-resonance in our model. Our findings may be useful for
             lattice QCD studies. © 2008 The American Physical
             Society.},
   Doi = {10.1103/PhysRevD.77.091501},
   Key = {fds245705}
}

@article{Chandrasekharan:2006wn,
   Author = {Chandrasekharan, S and Jiang, F-J and Pepe, M and Wiese,
             U-J},
   Title = {Rotor spectra, berry phases, and monopole fields: From
             antiferromagnets to QCD},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {78},
   Number = {7},
   Pages = {077901},
   Year = {2008},
   ISSN = {1550-7998},
   url = {http://arxiv.org/pdf/cond-mat/0612252},
   Abstract = {The order parameter of a finite system with a spontaneously
             broken continuous global symmetry acts as a quantum
             mechanical rotor. Both antiferromagnets with a spontaneously
             broken SU(2)s spin symmetry and massless QCD with a broken
             SU(2)L×SU(2)R chiral symmetry have rotor spectra when
             considered in a finite volume. When an electron or hole is
             doped into an antiferromagnet or when a nucleon is
             propagating through the QCD vacuum, a Berry phase arises
             from a monopole field and the angular momentum of the rotor
             is quantized in half-integer units. © 2008 The American
             Physical Society.},
   Doi = {10.1103/PhysRevD.78.077901},
   Key = {Chandrasekharan:2006wn}
}

@article{fds245707,
   Author = {Jiang, F-J and Nyfeler, M and Chandrasekharan, S and Wiese,
             U-J},
   Title = {From an antiferromagnet to a valence bond solid: Evidence
             for a first-order phase transition},
   Journal = {Journal of statistical mechanics (Online)},
   Volume = {2008},
   Number = {2},
   Pages = {P02009},
   Year = {2008},
   ISSN = {1742-5468},
   url = {http://iopscience.iop.org/1742-5468/2008/02/P02009/},
   Abstract = {Using a loop-cluster algorithm we investigate the spin-
             Heisenberg antiferromagnet on a square lattice with exchange
             coupling J and an additional four-spin interaction of
             strength Q. We confirm the existence of a phase transition
             separating antiferromagnetism at J/Q>Jc/Q from a valence
             bond solid (VBS) state at J/Q<Jc/Q. Although our Monte
             Carlo data are consistent with those of previous studies, we
             do not confirm the existence of a deconfined quantum
             critical point. Instead, using a flowgram method on lattices
             as large as 802, we find evidence for a weak first-order
             phase transition. We also present a detailed study of the
             antiferromagnetic phase. For J/Q>Jc/Q the staggered
             magnetization, the spin stiffness and the spinwave velocity
             of the antiferromagnet are determined by fitting Monte Carlo
             data to analytic results from the systematic low-energy
             effective field theory for magnons. Finally, we also
             investigate the physics of the VBS state at J/Q<Jc/Q and
             we show that long but finite antiferromagnetic correlations
             are still present. © 2008 IOP Publishing
             Ltd.},
   Doi = {10.1088/1742-5468/2008/02/P02009},
   Key = {fds245707}
}

@article{fds245708,
   Author = {Cecile, DJ and Chandrasekharan, S},
   Title = {Absence of vortex condensation in a two dimensional
             fermionic XY model},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {77},
   Number = {5},
   Pages = {054502},
   Year = {2008},
   ISSN = {1550-7998},
   url = {http://link.aps.org/abstract/PRD/v77/e054502},
   Abstract = {Motivated by a puzzle in the study of two-dimensional
             lattice quantum electrodynamics with staggered fermions, we
             construct a two-dimensional fermionic model with a global
             U(1) symmetry. Our model can be mapped into a model of
             closed packed dimers and plaquettes. Although the model has
             the same symmetries as the XY model, we show numerically
             that the model lacks the well-known Kosterlitz-Thouless
             phase transition. The model is always in the gapless phase
             showing the absence of a phase with vortex condensation. In
             other words the low energy physics is described by a
             noncompact U(1) field theory. We show that by introducing an
             even number of layers one can introduce vortex condensation
             within the model and thus also induce a Kosterlitz-Thouless
             transition. © 2008 The American Physical
             Society.},
   Doi = {10.1103/PhysRevD.77.054502},
   Key = {fds245708}
}

@article{fds245709,
   Author = {Cecile, DJ and Chandrasekharan, S},
   Title = {Modeling pion physics in the -regime of two-flavor QCD using
             strong coupling lattice QED},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {77},
   Number = {1},
   Pages = {014506},
   Year = {2008},
   ISSN = {1550-7998},
   url = {http://link.aps.org/abstract/PRD/v77/e014506},
   Abstract = {In order to model pions of two-flavor QCD we consider a
             lattice field theory involving two flavors of staggered
             quarks interacting strongly with U(1) gauge fields. For
             massless quarks, this theory has an SUL(2)×SUR(2) ×UA(1)
             symmetry. By adding a four-fermion term we can break the
             UA(1) symmetry and thus incorporate the physics of the QCD
             anomaly. We can also tune the pion decay constant F, to be
             small compared to the lattice cutoff by starting with an
             extra fictitious dimension, thus allowing us to model low
             energy pion physics in a setting similar to lattice QCD from
             first principles. However, unlike lattice QCD, a major
             advantage of our model is that we can easily design
             efficient algorithms to compute a variety of quantities in
             the chiral limit. Here we show that the model reproduces the
             predictions of chiral perturbation theory in the -regime. ©
             2008 The American Physical Society.},
   Doi = {10.1103/PhysRevD.77.014506},
   Key = {fds245709}
}

@article{fds245712,
   Author = {Chandrasekharan, S and Mehta, AC},
   Title = {Effects of the anomaly on the two-flavor QCD chiral phase
             transition.},
   Journal = {Physical Review Letters},
   Volume = {99},
   Number = {14},
   Pages = {142004},
   Year = {2007},
   Month = {October},
   ISSN = {0031-9007},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/17930663},
   Abstract = {We use strongly coupled lattice QED with two flavors of
             massless staggered fermions to model the chiral phase
             transition in two-flavor massless QCD. Our model allows us
             to vary the QCD anomaly and thus study its effects on the
             transition. Our study confirms the widely accepted viewpoint
             that the chiral phase transition is first order in the
             absence of the anomaly. Turning on the anomaly weakens the
             transition and turns it second order at a critical anomaly
             strength. The anomaly strength at the tricritical point is
             characterized using r=(M(eta')-M(pi))/rho(eta'), where
             M(eta'), M(pi) are the screening masses of the anomalous and
             regular pions and rho(eta') is the mass scale that governs
             the low energy fluctuations of the anomalous symmetry. We
             estimate that r ~ 7 in our model. This suggests that a
             strong anomaly at the two-flavor QCD chiral phase transition
             is necessary to wash out the first order
             transition.},
   Doi = {10.1103/PhysRevLett.99.142004},
   Key = {fds245712}
}

@article{fds303652,
   Author = {Chandrasekharan, S and Mehta, AC},
   Title = {Effects of the anomaly on the two-flavor QCD chiral phase
             transition},
   Journal = {Phys.Rev.Lett.},
   Volume = {99},
   Pages = {142004},
   Year = {2007},
   Month = {May},
   url = {http://arxiv.org/abs/0705.0617v1},
   Abstract = {We use strongly coupled lattice QED with two flavors of
             massless staggered fermions to model the physics of pions in
             two-flavor massless QCD. Our model has the right chiral
             symmetries and can be studied efficiently with cluster
             algorithms. In particular we can tune the strength of the
             QCD anomaly and thus study its effects on the chiral phase
             transition. Our study confirms the widely accepted view
             point that the chiral phase transition is first order in the
             absence of the anomaly. Turning on the anomaly weakens the
             transition and turns it second order at a critical anomaly
             strength. The anomaly strength at the tricritical point is
             characterized using $r = (M_{\eta'}-M_{\pi})/\rho_{\eta'}$
             where $M_{\eta'}, M_{\pi}$ are the screening masses of the
             anomalous and regular pions and $\rho_{\eta'}$ is the
             mass-scale that governs the low energy fluctuations of the
             anomalous symmetry. We estimate that $r \sim 7 $ in our
             model. This suggests that a strong anomaly at the two-flavor
             QCD chiral phase transition is necessary to wash out the
             first order transition.},
   Doi = {10.1103/PhysRevLett.99.142004},
   Key = {fds303652}
}

@article{Chandrasekharan:2007up,
   Author = {Chandrasekharan, Shailesh and Mehta, Abhijit
             C.},
   Title = {Effects of the anomaly on the two-flavor QCD chiral phase
             transition},
   Journal = {Phys. Rev. Lett.},
   Volume = {99},
   Pages = {142004},
   Year = {2007},
   url = {http://arxiv.org/pdf/0705.0617},
   Abstract = {http://arxiv.org/abs/0705.0617},
   Key = {Chandrasekharan:2007up}
}

@article{fds245710,
   Author = {Podolsky, D and Berkeley, UC and Chandrasekharan, S and Vishwanath,
             A and Berkeley, UC and Berkeley, LBL},
   Title = {Novel transitions in S=1 spinor condensates and XY
             Ashkin-Teller universality},
   Journal = {arXiv:0707.0695 [cond-mat.stat-mech]},
   Year = {2007},
   Abstract = {We study spin-1 polar spinor condensates with magnetic
             anisotropy, in two spatial dimensions at finite
             temperatures. The topological binding of vorticity to
             nematic disclinations leads to a rich phase diagram, which
             is captured by a U(1) version of the Ashkin-Teller model. In
             particular, a "cascaded" Kosterlitz-Thouless critical point,
             with two diverging scales, is predicted. Numerical
             simulations are performed to check our picture.},
   Key = {fds245710}
}

@article{fds303651,
   Author = {Lee, J-W and Chandrasekharan, S and Baranger, HU},
   Title = {Disorder-Induced Superfluidity in Hardcore Bosons in Two
             Dimensions},
   Year = {2006},
   Month = {November},
   url = {http://arxiv.org/abs/cond-mat/0611109v1},
   Abstract = {We study the effect of disorder on hardcore bosons in two
             dimensions at the SU(2) symmetric ``Heisenberg point''. We
             obtain our results with quantum Monte Carlo simulations
             using the directed loop algorithm. In the absence of
             disorder, the system has no long-range order at finite
             temperature due to the enhanced symmetry. However, the
             introduction of a disordered potential, uniformly
             distributed from -D to D, induces a finite-temperature
             superfluid phase. In particular the diagonal correlation
             length \xi decreases but the superfluid order-parameter
             correlation function becomes a power-law. A non-monotonic
             finite-size behavior is noted and explained as arising due
             to \xi. We provide evidence that at long distances the
             effects of a weak disordered potential can be mimicked by an
             effective uniform potential with a root-mean-square value:
             mu_eff = D/sqrt{3}. For strong disorder, the system becomes
             a Bose glass insulator.},
   Key = {fds303651}
}

@article{fds245714,
   Author = {Chandrasekharan, S},
   Title = {Anomalous superfluidity in (2+1)-dimensional two-color
             lattice QCD.},
   Journal = {Physical Review Letters},
   Volume = {97},
   Number = {18},
   Pages = {182001},
   Year = {2006},
   Month = {November},
   ISSN = {0031-9007},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/17155536},
   Abstract = {We study thermodynamics of strongly coupled lattice QCD with
             two colors of staggered fermions in 2+1 dimensions. The
             partition function of this model can be written elegantly as
             a statistical mechanics of dimers and baryon loops. The
             model is invariant under an SO(3) x U(1) symmetry. At low
             temperatures, we find evidence for superfluidity in the U(1)
             symmetry sector while the SO(3) symmetry remains unbroken.
             The finite temperature phase transition appears to belong to
             the Kosterlitz-Thouless universality class, but the
             superfluid density jump rho(s) (T(c)) at the critical
             temperature T(c) is anomalously higher than the normal value
             of 2T(c)/pi. We show that, by adding a small SO(3) symmetry
             breaking term to the model, the superfluid density jump
             returns to its normal value, implying that the extra
             symmetry causes anomalous superfluid behavior. Our results
             may be of interest to researchers studying superfluidity in
             spin-1 systems.},
   Doi = {10.1103/PhysRevLett.97.182001},
   Key = {fds245714}
}

@article{PhysRevLett.97.115703,
   Author = {Priyadarshee, A and Chandrasekharan, S and Lee, J-W and Baranger,
             HU},
   Title = {Quantum phase transitions of hard-core bosons in background
             potentials.},
   Journal = {Physical Review Letters},
   Volume = {97},
   Number = {11},
   Pages = {115703},
   Year = {2006},
   Month = {September},
   ISSN = {0031-9007},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/17025902},
   Abstract = {We study the zero temperature phase diagram of hard-core
             bosons in two dimensions subjected to three types of
             background potentials: staggered, uniform, and random. In
             all three cases there is a quantum phase transition from a
             superfluid (at small potential) to a normal phase (at large
             potential), but with different universality classes. As
             expected, the staggered case belongs to the XY universality,
             while the uniform potential induces a mean field transition.
             The disorder driven transition is clearly different from
             both; in particular, we find z approximately 1.4, nu
             approximately 1, and beta approximately 0.6.},
   Doi = {10.1103/PhysRevLett.97.115703},
   Key = {PhysRevLett.97.115703}
}

@article{fds245711,
   Author = {Kaul, RK and Zaránd, G and Chandrasekharan, S and Ullmo, D and Baranger, HU},
   Title = {Spectroscopy of the Kondo problem in a box.},
   Journal = {Physical Review Letters},
   Volume = {96},
   Number = {17},
   Pages = {176802},
   Year = {2006},
   Month = {May},
   ISSN = {0031-9007},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/16712322},
   Abstract = {Motivated by experiments on double quantum dots, we study
             the problem of a single magnetic impurity confined in a
             finite metallic host. We prove an exact theorem for the
             ground state spin, and use analytic and numerical arguments
             to map out the spin structure of the excitation spectrum of
             the many-body Kondo-correlated state, throughout the weak to
             strong coupling crossover. These excitations can be probed
             in a simple tunneling-spectroscopy transport experiment; for
             that situation we solve rate equations for the
             conductance.},
   Doi = {10.1103/PhysRevLett.96.176802},
   Key = {fds245711}
}

@article{lee-2006,
   Author = {Lee, Ji-Woo and Chandrasekharan, Shailesh and Baranger,
             Harold U.},
   Title = {Disorder-Induced Superfluidity in Hardcore Bosons in Two
             Dimensions},
   Year = {2006},
   url = {http://arxiv.org/pdf/arXiv:0705.0617 [hep-lat]},
   Abstract = {http://arxiv.org/abs/arXiv:0705.0617 [hep-lat]},
   Key = {lee-2006}
}

@article{PhysRevLett.97.182001,
   Author = {Chandrasekharan, Shailesh},
   Title = {Anomalous Superfluidity in $(2+1)$-Dimensional Two-Color
             Lattice QCD},
   Journal = {Phys. Rev. Lett.},
   Volume = {97},
   Number = {18},
   Pages = {182001},
   Year = {2006},
   Key = {PhysRevLett.97.182001}
}

@article{PhysRevLett.96.176802,
   Author = {Kaul, Ribhu K. and Zar\'and, Gergely and Chandrasekharan,
             Shailesh and Ullmo, Denis and Baranger, Harold
             U.},
   Title = {Spectroscopy of the Kondo Problem in a Box},
   Journal = {Phys. Rev. Lett.},
   Volume = {96},
   Number = {17},
   Pages = {176802},
   Year = {2006},
   Key = {PhysRevLett.96.176802}
}

@article{Chandrasekharan:2006tz,
   Author = {Chandrasekharan, Shailesh and Jiang, Fu-Jiun},
   Title = {Phase-diagram of two-color lattice QCD in the chiral
             limit},
   Journal = {Phys. Rev.},
   Volume = {D74},
   Pages = {014506},
   Year = {2006},
   url = {http://arxiv.org/pdf/hep-lat/0602031},
   Abstract = {http://arxiv.org/abs/hep-lat/0602031},
   Key = {Chandrasekharan:2006tz}
}

@article{Chandrasekharan:2006iw,
   Author = {Chandrasekharan, S},
   Title = {New approaches to strong coupling lattice
             QCD},
   Journal = {Int. J. Mod. Phys.},
   Volume = {B20},
   Pages = {2714-2723},
   Year = {2006},
   Key = {Chandrasekharan:2006iw}
}

@article{fds245713,
   Author = {Chandrasekharan, S and Jiang, F-J},
   Title = {Phase diagram of two-color lattice QCD in the chiral
             limit},
   Journal = {Physical Review D - Particles, Fields, Gravitation, and
             Cosmology},
   Volume = {74},
   Number = {1},
   Pages = {014506},
   Year = {2006},
   ISSN = {1550-7998},
   url = {http://link.aps.org/doi/10.1103/PhysRevD.74.014506},
   Abstract = {We study thermodynamics of strongly coupled lattice QCD with
             two colors of massless staggered fermions as a function of
             the baryon chemical potential μ in 3+1 dimensions using a
             new cluster algorithm. We find evidence that the model
             undergoes a weak first order phase transition at μ=0 which
             becomes second order at a finite μ. Symmetry considerations
             suggest that the universality class of these phase
             transitions should be governed by a O(N)×O(2) field theory
             with collinear order, with N=3 at μ=0 and N=2 at μ≠0.
             The universality class of the second order phase transition
             at μ≠0 appears to be governed by the decoupled XY fixed
             point present in the O(2)×O(2) field theory. Finally we
             show that the quantum (T=0) phase transition as a function
             of μ is a second order mean field transition. © 2006 The
             American Physical Society.},
   Doi = {10.1103/PhysRevD.74.014506},
   Key = {fds245713}
}

@article{Chandrasekharan:2005dn,
   Author = {Chandrasekharan, S and Jiang, F-J},
   Title = {Chiral limit of 2-color QCD at strong couplings},
   Journal = {PoS LAT},
   Volume = {2005},
   Pages = {198},
   Year = {2005},
   Month = {September},
   url = {http://arxiv.org/abs/hep-lat/0509117v1},
   Abstract = {We study two-color lattice QCD with massless staggered
             fermions in the strong coupling limit using a new and
             efficient cluster algorithm. We focus on the phase diagram
             of the model as a function of temperature $T$ and baryon
             chemical potential $\mu$ by working on $L_t \times L^d$
             lattices in both $d=2,3$. In $d=3$ we find that at $\mu=0$
             the ground state of the system breaks the global U(2)
             symmetry present in the model to U(1), while the finite
             temperature phase transition (with $L_t=4$) which restores
             the symmetry is a weak first order transition. In $d=2$ we
             find evidence for a novel phase transition similar to the
             Berezinky-Kosterlitz-Thouless phenomena. On the other hand
             the quantum (T=0) phase transition to a symmetric phase as a
             function of $\mu$ is second order in both $d=2,3$ and
             belongs to the mean field universality class.},
   Key = {Chandrasekharan:2005dn}
}

@article{Yoo:2004mh,
   Author = {Yoo, J and Chandrasekharan, S and Baranger, HU},
   Title = {Multilevel algorithm for quantum-impurity
             models.},
   Journal = {Physical Review E - Statistical, Nonlinear, and Soft Matter
             Physics},
   Volume = {71},
   Number = {3 Pt 2B},
   Pages = {036708},
   Year = {2005},
   Month = {March},
   ISSN = {1539-3755},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/15903634},
   Abstract = {A continuous-time path integral quantum Monte Carlo method
             using the directed-loop algorithm is developed to simulate
             the Anderson single-impurity model in the occupation number
             basis. Although the method suffers from a sign problem at
             low temperatures, the new algorithm has many advantages over
             conventional algorithms. For example, the model can be
             easily simulated in the Kondo limit without time
             discretization errors. Furthermore, many observables
             including the impurity susceptibility and a variety of
             fermionic observables can be calculated efficiently. Finally
             the new approach allows us to explore a general technique,
             called the multilevel algorithm, to solve the sign problem.
             We find that the multilevel algorithm is able to generate an
             exponentially large number of configurations with an effort
             that grows as a polynomial in inverse temperature such that
             configurations with a positive sign dominate over those with
             negative signs. Our algorithm can be easily generalized to
             other multi-impurity problems.},
   Doi = {10.1103/PhysRevE.71.036708},
   Key = {Yoo:2004mh}
}

@article{fds245715,
   Author = {Chandrasekharan, S and Strouthos, CG},
   Title = {Failure of mean field theory at large N.},
   Journal = {Physical Review Letters},
   Volume = {94},
   Number = {6},
   Pages = {061601},
   Year = {2005},
   Month = {February},
   ISSN = {0031-9007},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/15783719},
   Abstract = {We study strongly coupled lattice QCD with N colors of
             staggered fermions in 3+1 dimensions. While mean field
             theory describes the low temperature behavior of this theory
             at large N, it fails in the scaling region close to the
             finite temperature second order chiral phase transition. The
             universal critical region close to the phase transition
             belongs to the 3D XY universality class even when N becomes
             large. This is in contrast to Gross-Neveu models where the
             critical region shrinks as N (the number of flavors)
             increases and mean field theory is expected to describe the
             phase transition exactly in the limit of infinite N. Our
             work demonstrates that infrared fluctuations can be
             important close to second order phase transitions even when
             N is strictly infinite.},
   Doi = {10.1103/PhysRevLett.94.061601},
   Key = {fds245715}
}

@article{Chandrasekharan:2004uw,
   Author = {Chandrasekharan, Shailesh and Strouthos, Costas
             G.},
   Title = {Failure of mean field theory at large N},
   Journal = {Phys. Rev. Lett.},
   Volume = {94},
   Pages = {061601},
   Year = {2005},
   url = {http://arxiv.org/pdf/hep-lat/0410036},
   Abstract = {http://arxiv.org/abs/hep-lat/0410036},
   Key = {Chandrasekharan:2004uw}
}

@article{PhysRevB.72.024525,
   Author = {Lee, J-W and Chandrasekharan, S and Baranger, HU},
   Title = {Quantum Monte Carlo study of disordered fermions},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {72},
   Number = {2},
   Pages = {024525},
   Year = {2005},
   ISSN = {1098-0121},
   url = {http://dx.doi.org/10.1103/PhysRevB.72.024525},
   Abstract = {We study a strongly correlated fermionic model with
             attractive interactions in the presence of disorder in two
             spatial dimensions. Our model has been designed so that it
             can be solved using the recently discovered meron-cluster
             approach. Although the model is unconventional it has the
             same symmetries as the Hubbard model. Since the naive
             algorithm is inefficient, we develop an algorithm by
             combining the meron-cluster technique with the directed-loop
             update. This combination allows us to compute the pair
             susceptibility and the winding number susceptibility
             accurately. We find that the s -wave superconductivity,
             present in the clean model, does not disappear until the
             disorder reaches a temperature dependent critical strength.
             The critical behavior as a function of disorder close to the
             phase transition belongs to the Berezinky-Kosterlitz-Thouless
             universality class as expected. The fermionic degrees of
             freedom, although present, do not appear to play an
             important role near the phase transition. © 2005 The
             American Physical Society.},
   Doi = {10.1103/PhysRevB.72.024525},
   Key = {PhysRevB.72.024525}
}

@article{Kaul04_mesokondo,
   Author = {Kaul, RK and Ullmo, D and Chandrasekharan, S and Baranger,
             HU},
   Title = {Mesoscopic Kondo problem},
   Journal = {Europhysics Letters},
   Volume = {71},
   Number = {6},
   Pages = {973-979},
   Year = {2005},
   url = {http://www.phy.duke.edu/research/cmtheory/bg/paper/kaulucb04_mesokondo.pdf},
   Abstract = {We study the effect of mesoscopic fluctuations on a magnetic
             impurity coupled to a spatially confined electron gas with a
             temperature in the mesoscopic range (i.e. between the mean
             level spacing Δ and the Thouless energy ETh). Comparing
             "poor-man's scaling" with exact Quantum Monte Carlo, we find
             that for temperatures larger than the Kondo temperature,
             many aspects of the fluctuations can be captured by the
             perturbative technique. Using this technique in conjunction
             with semi-classical approximations, we are able to calculate
             the mesoscopic fluctuations for a wide variety of systems.
             For temperatures smaller than the Kondo temperature, we find
             large fluctuations and deviations from the universal
             behavior. © EDP Sciences.},
   Doi = {10.1209/epl/i2005-10184-1},
   Key = {Kaul04_mesokondo}
}

@article{PhysRevB.71.201309,
   Author = {Yoo, J and Chandrasekharan, S and Kaul, RK and Ullmo, D and Baranger,
             HU},
   Title = {Cluster algorithms for quantum impurity models and
             mesoscopic Kondo physics},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {71},
   Number = {20},
   Pages = {201309},
   Year = {2005},
   url = {http://dx.doi.org/10.1103/PhysRevB.71.201309},
   Abstract = {Nanoscale physics and dynamical mean-field theory have both
             generated increased interest in complex quantum impurity
             problems and so have focused attention on the need for
             flexible quantum impurity solvers. Here we demonstrate that
             the mapping of single-quantum impurity problems onto spin
             chains can be exploited to yield a powerful and extremely
             flexible impurity solver. We implement this cluster
             algorithm explicitly for the Anderson and Kondo
             Hamiltonians, and illustrate its use in the "mesoscopic
             Kondo problem." To study universal Kondo physics, a large
             ratio between the effective bandwidth Deff and the
             temperature T is required; our cluster algorithm treats the
             mesoscopic fluctuations exactly while being able to approach
             the large Deff T limit with ease. We emphasize that the
             flexibility of our method allows it to tackle a wide variety
             of quantum impurity problems; thus, it may also be relevant
             to the dynamical mean-field theory of lattice problems. ©
             2005 The American Physical Society.},
   Doi = {10.1103/PhysRevB.71.201309},
   Key = {PhysRevB.71.201309}
}

@article{Yoo05_HFsign,
   Author = {Yoo, J and Chandrasekharan, S and Kaul, RK and Ullmo, D and Baranger,
             HU},
   Title = {On the sign problem in the Hirsch-Fye algorithm for impurity
             problems},
   Journal = {Journal of Physics A: Mathematical and General},
   Volume = {38},
   Number = {48},
   Pages = {10307-10310},
   Year = {2005},
   url = {http://www.phy.duke.edu/research/cmtheory/bg/paper/yooCKUB05_hfsign.pdf},
   Abstract = {We show that there is no fermion sign problem in the Hirsch
             and Fye algorithm for the single-impurity Anderson model.
             Beyond the particle-hole symmetric case for which a simple
             proof exists, this has been known only empirically. Here we
             prove the nonexistence of a sign problem for the general
             case by showing that each spin trace for a given Ising
             configuration is separately positive. We further use this
             insight to analyse under what conditions orbitally
             degenerate Anderson models or the two-impurity Anderson
             model develop a sign. © 2005 IOP Publishing
             Ltd.},
   Doi = {10.1088/0305-4470/38/48/004},
   Key = {Yoo05_HFsign}
}

@article{Chandrasekharan:2004kd,
   Author = {Chandrasekharan, Shailesh and Strouthos, Costas
             G.},
   Title = {Connecting lattice QCD with chiral perturbation theory at
             strong coupling},
   Journal = {Phys. Rev. D},
   Volume = {69},
   Pages = {091502},
   Year = {2004},
   url = {http://arxiv.org/pdf/hep-lat/0401002},
   Abstract = {http://arxiv.org/abs/hep-lat/0401002},
   Key = {Chandrasekharan:2004kd}
}

@article{Brower:2003vy,
   Author = {Brower, R. and Chandrasekharan, S. and Riederer, S. and Wiese, U. J.},
   Title = {D-theory: Field quantization by dimensional reduction of
             discrete variables},
   Journal = {Nucl. Phys. B},
   Volume = {693},
   Pages = {149-175},
   Year = {2004},
   url = {http://arxiv.org/pdf/hep-lat/0309182},
   Abstract = {http://arxiv.org/abs/hep-lat/0309182},
   Key = {Brower:2003vy}
}

@book{fds16196,
   Author = {S. Chandrasekharan and U.-J. Wiese},
   Title = {AN INTRODUCTION TO CHIRAL SYMMETRY ON THE
             LATTICE},
   Booktitle = {Prog. Part. Nucl. Phys. Vol. 53, issue 1,},
   Year = {2004},
   Key = {fds16196}
}

@article{Chandrasekharan:2004cn,
   Author = {Chandrasekharan, S and Wiese, U-J},
   Title = {An introduction to chiral symmetry on the
             lattice},
   Journal = {Progress in Particle and Nuclear Physics},
   Volume = {53},
   Number = {2},
   Pages = {373-418},
   Year = {2004},
   url = {http://arxiv.org/pdf/hep-lat/0405024},
   Abstract = {The SU(Nf)L⊗SU(Nf)R chiral symmetry of QCD is of central
             importance for the nonperturbative low-energy dynamics of
             light quarks and gluons. Lattice field theory provides a
             theoretical framework in which these dynamics can be studied
             from first principles. The implementation of chiral symmetry
             on the lattice is a nontrivial issue. In particular, local
             lattice fermion actions with the chiral symmetry of the
             continuum theory suffer from the fermion doubling problem.
             The Ginsparg-Wilson relation implies Lüscher's lattice
             variant of chiral symmetry which agrees with the usual one
             in the continuum limit. Local lattice fermion actions that
             obey the Ginsparg-Wilson relation have an exact chiral
             symmetry, the correct axial anomaly, they obey a lattice
             version of the Atiyah-Singer index theorem, and still they
             do not suffer from the notorious doubling problem. The
             Ginsparg-Wilson relation is satisfied exactly by Neuberger's
             overlap fermions which are a limit of Kaplan's domain wall
             fermions, as well as by Hasenfratz and Niedermayer's
             classically perfect lattice fermion actions. When chiral
             symmetry is nonlinearly realized in effective field theories
             on the lattice, the doubling problem again does not arise.
             This review provides an introduction to chiral symmetry on
             the lattice with an emphasis on the basic theoretical
             framework. © 2004 Published by Elsevier
             B.V.},
   Doi = {10.1016/j.ppnp.2004.05.003},
   Key = {Chandrasekharan:2004cn}
}

@article{Chandrasekharan:2003ug,
   Author = {Chandrasekharan, S},
   Title = {Chiral and critical in strong coupling QCD},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {129-130},
   Pages = {578-580},
   Year = {2004},
   url = {http://arxiv.org/pdf/hep-lat/0309098},
   Abstract = {We use a cluster algorithm to study the critical behavior of
             strongly coupled lattice QCD in the chiral limit. We show
             that the finite temperature chiral phase transition belongs
             to the O(2) universality class as expected. When we compute
             the finite size effects of the chiral susceptibility in the
             low temperature phase close to the transition, we find clear
             evidence for chiral singularities predicted by chiral
             perturbation theory (ChPT). On the other hand it is
             difficult to reconcile the quark mass dependence of various
             quantities near the chiral limit with ChPT. © 2004
             Published by Elsevier B.V.},
   Doi = {10.1016/S0920-5632(03)02647-1},
   Key = {Chandrasekharan:2003ug}
}

@article{Chandrasekharan:2003ub,
   Author = {Chandrasekharan, S and Pepe, M and Steffen, FD and Wiese,
             U-J},
   Title = {Lattice theories with nonlinearly realized chiral
             symmetry},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {129-130},
   Pages = {507-509},
   Year = {2004},
   url = {http://arxiv.org/pdf/hep-lat/0309093},
   Abstract = {We present the lattice formulation of effective Lagrangians
             in which chiral symmetry is realized nonlinearly on the
             fermion fields. In this framework both the Wilson term
             removing unphysical doubler fermions and the fermion mass
             term do not break chiral symmetry. Our lattice formulation
             allows us to address non-perturbative questions in effective
             theories of baryons interacting with pions and in models
             involving constitutent quarks interacting with pions and
             gluons. With the presented methods, a system containing a
             non-zero density of static baryons interacting with pions
             can be studied on the lattice without encountering a complex
             action problem. This might lead to new insights into the
             phase diagram of strongly interacting matter at non-zero
             chemical potential. © 2004 Elsevier B.V. All rights
             reserved.},
   Doi = {10.1016/S0920-5632(03)02624-0},
   Key = {Chandrasekharan:2003ub}
}

@article{fds245717,
   Author = {Brower, R and Chandrasekharan, S and Riederer, S and Wiese,
             U-J},
   Title = {D-theory: Field quantization by dimensional reduction of
             discrete variables},
   Journal = {Nuclear Physics B},
   Volume = {693},
   Number = {1-3},
   Pages = {149-175},
   Year = {2004},
   url = {http://dx.doi.org/10.1016/j.nuclphysb.2004.06.007},
   Abstract = {D-theory is an alternative non-perturbative approach to
             quantum field theory formulated in terms of discrete
             quantized variables instead of classical fields. Classical
             scalar fields are replaced by generalized quantum spins and
             classical gauge fields are replaced by quantum links. The
             classical fields of a d-dimensional quantum field theory
             reappear as low-energy effective degrees of freedom of the
             discrete variables, provided the (d+1)-dimensional D-theory
             is massless. When the extent of the extra Euclidean
             dimension becomes small in units of the correlation length,
             an ordinary d-dimensional quantum field theory emerges by
             dimensional reduction. The D-theory formulation of scalar
             field theories with various global symmetries and of gauge
             theories with various gauge groups is constructed explicitly
             and the mechanism of dimensional reduction is investigated.
             © 2004 Elsevier B.V. All rights reserved.},
   Doi = {10.1016/j.nuclphysb.2004.06.007},
   Key = {fds245717}
}

@article{fds245720,
   Author = {Chandrasekharan, S and Strouthos, CG},
   Title = {Connecting lattice QCD with chiral perturbation theory at
             strong coupling},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {69},
   Number = {9},
   Pages = {091502},
   Year = {2004},
   ISSN = {0556-2821},
   url = {http://dx.doi.org/10.1103/PhysRevD.69.091502},
   Abstract = {We study the difficulties associated with detecting chiral
             singularities predicted by chiral perturbation theory (ChPT)
             in lattice QCD. We focus on the physics of the remnant O(2)
             chiral symmetry of staggered fermions in the strong coupling
             limit using the recently discovered directed path algorithm.
             Since it is easier to look for powerlike singularities as
             compared to logarithmic ones, our calculations are performed
             at a fixed finite temperature in the chirally broken phase.
             We show that the behavior of the chiral condensate, the pion
             mass, and the pion decay constant are all consistent with
             the predictions of ChPT for small masses. However, in order
             to demonstrate this we need quark masses that are much
             smaller (in lattice units) than those typically used in
             dynamical QCD simulations. We also need to use higher order
             terms in the chiral expansion to fit our data. © 2004 The
             American Physical Society.},
   Doi = {10.1103/PhysRevD.69.091502},
   Key = {fds245720}
}

@article{fds303653,
   Author = {Chandrasekharan, S and Pepe, M and Steffen, FD and Wiese,
             U-J},
   Title = {Nonlinear Realization of Chiral Symmetry on the
             Lattice},
   Journal = {JHEP},
   Volume = {0312},
   Pages = {035},
   Year = {2003},
   Month = {June},
   url = {http://arxiv.org/abs/hep-lat/0306020v2},
   Abstract = {We formulate lattice theories in which chiral symmetry is
             realized nonlinearly on the fermion fields. In this
             framework the fermion mass term does not break chiral
             symmetry. This property allows us to use the Wilson term to
             remove the doubler fermions while maintaining exact chiral
             symmetry on the lattice. Our lattice formulation enables us
             to address non-perturbative questions in effective field
             theories of baryons interacting with pions and in models
             involving constituent quarks interacting with pions and
             gluons. We show that a system containing a non-zero density
             of static baryons interacting with pions can be studied on
             the lattice without encountering complex action problems. In
             our formulation one can also decide non-perturbatively if
             the chiral quark model of Georgi and Manohar provides an
             appropriate low-energy description of QCD. If so, one could
             understand why the non-relativistic quark model
             works.},
   Doi = {10.1088/1126-6708/2003/12/035},
   Key = {fds303653}
}

@article{Chandrasekharan:2002vk,
   Author = {Chandrasekharan, S. and Cox, J. and Osborn, J. C. and Wiese,
             U. J.},
   Title = {Meron-Cluster Approach to Systems of Strongly Correlated
             Electrons},
   Journal = {Nucl. Phys. B},
   Volume = {673},
   Pages = {405-436},
   Year = {2003},
   url = {http://arxiv.org/pdf/cond-mat/0201360},
   Abstract = {http://arxiv.org/abs/cond-mat/0201360},
   Key = {Chandrasekharan:2002vk}
}

@article{Chandrasekharan:2003im,
   Author = {Chandrasekharan, Shailesh and Jiang, Fu-Jiun},
   Title = {Chiral limit of strongly coupled lattice QCD at finite
             temperatures},
   Journal = {Phys. Rev. D},
   Volume = {68},
   Pages = {091501},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0309025},
   Abstract = {http://arxiv.org/abs/hep-lat/0309025},
   Key = {Chandrasekharan:2003im}
}

@article{Chandrasekharan:2003eu,
   Author = {Chandrasekharan, S.},
   Title = {Connections between quantum chromodynamics and condensed
             matter physics},
   Journal = {Pramana},
   Volume = {61},
   Pages = {901-910},
   Year = {2003},
   Key = {Chandrasekharan:2003eu}
}

@article{Adams:2003cc,
   Author = {Adams, David H. and Chandrasekharan, Shailesh},
   Title = {Chiral limit of strongly coupled lattice gauge
             theories},
   Journal = {Nucl. Phys. B},
   Volume = {662},
   Pages = {220-246},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0303003},
   Abstract = {http://arxiv.org/abs/hep-lat/0303003},
   Key = {Adams:2003cc}
}

@article{Chandrasekharan:2003wy,
   Author = {Chandrasekharan, S. and Pepe, M. and Steffen, F. D. and Wiese, U. J.},
   Title = {Nonlinear realization of chiral symmetry on the
             lattice},
   Journal = {JHEP},
   Volume = {12},
   Pages = {035},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0306020},
   Abstract = {http://arxiv.org/abs/hep-lat/0306020},
   Key = {Chandrasekharan:2003wy}
}

@article{Chandrasekharan:2003qv,
   Author = {Chandrasekharan, Shailesh and Strouthos, Costas
             G.},
   Title = {Kosterlitz-Thouless universality in dimer
             models},
   Journal = {Phys. Rev. D},
   Volume = {68},
   Pages = {091502},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0306034},
   Abstract = {http://arxiv.org/abs/hep-lat/0306034},
   Key = {Chandrasekharan:2003qv}
}

@article{fds29982,
   Author = {S. Chandrasekharan},
   Title = {CHIRAL LIMIT OF STAGGERED FERMIONS AT STRONG COUPLINGS: A
             LOOP REPRESENTATION},
   Journal = {Nucl. Phys. B (Proceedings Suppl.)},
   Volume = {119},
   Pages = {929},
   Editor = {Edwards, Negele and Richards},
   Year = {2003},
   Abstract = {The partition function of two dimensional massless staggered
             fermions interacting with U(N) gauge fields is rewritten in
             terms of loop variables in the strong coupling limit. We use
             this representation of the theory to devise a non-local
             Metropolis algorithm to calculate the chiral susceptibility.
             For small lattices our algorithm reproduces exact results
             quite accurately. Applying this algorithm to large volumes
             yields rather surprising results. In particular we find
             $m_\pi \neq 0$ for all $N$ and it increases with $N$. Since
             the talk was presented we have found reasons to believe that
             our algorithm breaks down for large volumes questioning the
             validity of our results.},
   Key = {fds29982}
}

@article{fds245676,
   Author = {Chandrasekharan, S and Pepe, M and Steffen, FD and Wiese,
             U-J},
   Title = {Nonlinear realization of chiral symmetry on the
             lattice},
   Journal = {The Journal of High Energy Physics},
   Volume = {7},
   Number = {12},
   Pages = {831-863},
   Year = {2003},
   ISSN = {1029-8479},
   Abstract = {We formulate lattice theories in which chiral symmetry is
             realized nonlinearly on the fermion fields. In this
             framework the fermion mass term does not break chiral
             symmetry. This property allows us to use the Wilson term to
             remove the doubler fermions while maintaining exact chiral
             symmetry on the lattice. Our lattice formulation enables us
             to address non-perturbative questions in effective field
             theories of baryons interacting with pions and in models
             involving constituent quarks interacting with pions and
             gluons. We show that a system containing a non-zero density
             of static baryons interacting with pions can be studied on
             the lattice without encountering complex action problems. In
             our formulation one can also decide non-perturbatively if
             the chiral quark model of Georgi and Manohar provides an
             appropriate low-energy description of QCD. If so, one could
             understand why the non-relativistic quark model works. ©
             SISSA/ISAS 2004.},
   Key = {fds245676}
}

@article{Brower:2003yx,
   Author = {Brower, R and Chandrasekharan, S and Negele, JW and Wiese,
             U-J},
   Title = {QCD at fixed topology},
   Journal = {Physics Letters, Section B: Nuclear, Elementary Particle and
             High-Energy Physics},
   Volume = {560},
   Number = {1-2},
   Pages = {64-74},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0302005},
   Abstract = {Since present Monte Carlo algorithms for lattice QCD may
             become trapped in a fixed topological charge sector, it is
             important to understand the effect of calculating at fixed
             topology. In this Letter, we show that although the
             restriction to a fixed topological sector becomes irrelevant
             in the infinite volume limit, it gives rise to
             characteristic finite-size effects due to contributions from
             all θ-vacua. We calculate these effects and show how to
             extract physical results from numerical data obtained at
             fixed topology. © 2003 Published by Elsevier Science
             B.V.},
   Doi = {10.1016/S0370-2693(03)00369-1},
   Key = {Brower:2003yx}
}

@article{Chandrasekharan:2002gp,
   Author = {Chandrasekharan, S},
   Title = {Chiral limit of staggered fermions at strong couplings: A
             loop representation},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {119},
   Pages = {929-931},
   Year = {2003},
   url = {http://arxiv.org/pdf/hep-lat/0208071},
   Abstract = {The partition function of two dimensional massless staggered
             fermions interacting with U(N) gauge fields is rewritten in
             terms of loop variables in the strong coupling limit. We use
             this representation of the theory to devise a non-local
             Metropolis algorithm to calculate the chiral susceptibility.
             For small lattices our algorithm reproduces exact results
             quite accurately. Applying this algorithm to large volumes
             yields rather surprising results. In particular we find mπ
             ≠ 0 for all N and it increases with N. Since the talk was
             presented we have found reasons to believe that our
             algorithm breaks down for large volumes questioning the
             validity of our results.},
   Doi = {10.1016/S0920-5632(03)01722-5},
   Key = {Chandrasekharan:2002gp}
}

@article{fds245716,
   Author = {Chandrasekharan, S},
   Title = {Connections between quantum chromodynamics and condensed
             matter physics},
   Journal = {Pramana - Journal of Physics},
   Volume = {61},
   Number = {5},
   Pages = {901-910},
   Year = {2003},
   Abstract = {Features of QCD can be seen qualitatively in certain
             condensed matter systems. Recently some of the analyses that
             originated in condensed matter physics have found
             applications in QCD. Using examples we discuss some of the
             connections between the two fields and show how progress can
             be made by exploiting this connection. Some of the
             challenges that remain in the two fields are quite similar.
             We argue that recent algorithmic developments call for
             optimism in both fields.},
   Key = {fds245716}
}

@article{fds245718,
   Author = {Chandrasekharan, S and Strouthos, CG},
   Title = {Kosterlitz-Thouless universality in dimer
             models},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {68},
   Number = {9},
   Pages = {091502},
   Year = {2003},
   ISSN = {0556-2821},
   url = {http://dx.doi.org/10.1103/PhysRevD.68.091502},
   Abstract = {Using the monomer-dimer representation of strongly coupled
             U(N) lattice gauge theories with staggered fermions, we
             study finite temperature chiral phase transitions in 2+1
             dimensions. A new cluster algorithm allows us to compute
             monomer-monomer and dimer-dimer correlations at zero monomer
             density (chiral limit) accurately on large lattices. This
             makes it possible to show convincingly, for the first time,
             that these models undergo a finite temperature phase
             transition which belongs to the Kosterlitz-Thouless
             universality class. We find that the phase transition
             persists for all values of N, but occurs at different values
             of the critical temperature Tc. Further, when T /Tc is held
             fixed, the mean field analysis often used in the large N
             limit breaks down. © The American Physical
             Society.},
   Doi = {10.1103/PhysRevD.68.091502},
   Key = {fds245718}
}

@article{fds245719,
   Author = {Chandrasekharan, S and Jiang, F-J},
   Title = {Chiral limit of strongly coupled lattice QCD at finite
             temperatures},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {68},
   Number = {9},
   Pages = {091501},
   Year = {2003},
   ISSN = {0556-2821},
   url = {http://dx.doi.org/10.1103/PhysRevD.68.091501},
   Abstract = {We use the recently proposed directed-path algorithm to
             study the chiral limit of a strongly coupled lattice QCD
             with staggered quarks at finite temperatures. The new
             algorithm allows us to compute the chiral susceptibility and
             the pion decay constant accurately on large lattices for
             massless quarks. In the low temperature phase we find clear
             evidence for the singularities predicted by chiral
             perturbation theory. We also show convincingly that the
             chiral phase transition is of second order and belongs to
             the O(2) universality class. © The American Physical
             Society.},
   Doi = {10.1103/PhysRevD.68.091501},
   Key = {fds245719}
}

@article{fds245721,
   Author = {Chandrasekharan, S and Cox, J and Osborn, JC and Wiese,
             U-J},
   Title = {Meron-cluster approach to systems of strongly correlated
             electrons},
   Journal = {Nuclear Physics B},
   Volume = {673},
   Number = {3},
   Pages = {405-436},
   Year = {2003},
   url = {http://dx.doi.org/10.1016/j.nuclphysb.2003.08.041},
   Abstract = {Numerical simulations of strongly correlated electron
             systems suffer from the notorious fermion sign problem which
             has prevented progress in understanding if systems like the
             Hubbard model display high-temperature superconductivity.
             Here we show how the fermion sign problem can be solved
             completely with meron-cluster methods in a large class of
             models of strongly correlated electron systems, some of
             which are in the extended Hubbard model family and show
             s-wave superconductivity. In these models we also find that
             on-site repulsion can even coexist with a weak chemical
             potential without introducing sign problems. We argue that
             since these models can be simulated efficiently using
             cluster algorithms they are ideal for studying many of the
             interesting phenomena in strongly correlated electron
             systems. © 2003 Elsevier B.V. All rights
             reserved.},
   Doi = {10.1016/j.nuclphysb.2003.08.041},
   Key = {fds245721}
}

@article{fds245722,
   Author = {Adams, DH and Chandrasekharan, S},
   Title = {Chiral limit of strongly coupled lattice gauge
             theories},
   Journal = {Nuclear Physics B},
   Volume = {662},
   Number = {1-2},
   Pages = {220-246},
   Year = {2003},
   url = {http://dx.doi.org/10.1016/S0550-3213(03)00350-X},
   Abstract = {We construct a new and efficient cluster algorithm for
             updating strongly coupled U(N) lattice gauge theories with
             staggered fermions in the chiral limit. The algorithm uses
             the constrained monomer-dimer representation of the theory
             and should also be of interest to researchers working on
             other models with similar constraints. Using the new
             algorithm we address questions related to the chiral limit
             of strongly coupled U(N) gauge theories beyond the mean
             field approximation. We show that the infinite volume chiral
             condensate is non-zero in three and four dimensions.
             However, on a square lattice of size L we find
             ∑x〈ψ̄ψ(x)ψ̄ψ(0)〉∼ L2-η for large L where
             η=0.420(3)/N+0.078(4) /N2. These results differ from an
             earlier conclusion obtained using a different algorithm.
             Here we argue that the earlier calculations were misleading
             due to uncontrolled autocorrelation times encountered by the
             previous algorithm. © 2003 Elsevier Science B.V. All rights
             reserved.},
   Doi = {10.1016/S0550-3213(03)00350-X},
   Key = {fds245722}
}

@article{fds245723,
   Author = {Brower, R and Chandrasekharan, S and Negele, JW and Wiese,
             U-J},
   Title = {LATTICE QCD AT FIXED TOPOLOGY},
   Journal = {Phys. Lett. B},
   Volume = {560},
   Pages = {64-74},
   Year = {2003},
   Abstract = {Since present Monte Carlo algorithms for lattice QCD may
             become trapped in a fixed topological charge sector, it is
             important to understand the effect of calculating at fixed
             topology. In this work, we show that although the
             restriction to a fixed topological sector becomes irrelevant
             in the infinite volume limit, it gives rise to
             characteristic finite size effects due to contributions from
             all $\theta$-vacua. We calculate these effects and show how
             to extract physical results from numerical data obtained at
             fixed topology.},
   Key = {fds245723}
}

@article{Brower:2001cz,
   Author = {Brower, R. and Chandrasekharan, S. and Negele, J. W. and Wiese, U. J.},
   Title = {Physical observables from lattice QCD at fixed
             topology},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {106},
   Pages = {581-583},
   Year = {2002},
   url = {http://arxiv.org/pdf/hep-lat/0110121},
   Abstract = {http://arxiv.org/abs/hep-lat/0110121},
   Key = {Brower:2001cz}
}

@article{Chandrasekharan:2001ya,
   Author = {Chandrasekharan, S. and Scarlet, B. and Wiese, U.
             J.},
   Title = {From spin ladders to the 2-d O(3) model at non-zero
             density},
   Journal = {Comput. Phys. Commun.},
   Volume = {147},
   Pages = {388-393},
   Year = {2002},
   url = {http://arxiv.org/pdf/hep-lat/0110215},
   Abstract = {http://arxiv.org/abs/hep-lat/0110215},
   Key = {Chandrasekharan:2001ya}
}

@article{Chandrasekharan:2002ex,
   Author = {Chandrasekharan, Shailesh},
   Title = {Unexpected results in the chiral limit with staggered
             fermions},
   Journal = {Phys. Lett. B},
   Volume = {536},
   Pages = {72-78},
   Year = {2002},
   url = {http://arxiv.org/pdf/hep-lat/0203020},
   Abstract = {http://arxiv.org/abs/hep-lat/0203020},
   Key = {Chandrasekharan:2002ex}
}

@article{PhysRevB.66.045113,
   Author = {Chandrasekharan, S and Osborn, JC},
   Title = {Kosterlitz-Thouless universality in a fermionic
             system},
   Journal = {Physical Review B - Condensed Matter and Materials
             Physics},
   Volume = {66},
   Number = {4},
   Pages = {451131-451135},
   Year = {2002},
   ISSN = {0163-1829},
   Abstract = {An extension of the attractive Hubbard model is constructed
             to study the critical behavior near a finite-temperature
             superconducting phase transition in two dimensions using the
             recently developed meron-cluster algorithm. Unlike previous
             calculations in the attractive Hubbard model which were
             limited to small lattices, the algorithm is used to study
             the critical behavior on lattices as large as 128 × 128.
             These precise results show that a fermionic system can
             undergo a finite temperature phase transition whose critical
             behavior is well described by the predictions of Kosterlitz
             and Thouless almost three decades ago. In particular it is
             confirmed that the spatial winding number susceptibility
             obeys the well known predictions of finite size scaling for
             T <Tc and up to logarithmic corrections the pair
             susceptibility scales as L2-η at large volumes with 0 ≤
             η ≤ 0.25 for 0 ≤T≤T.},
   Key = {PhysRevB.66.045113}
}

@article{Chandrasekharan:2001dd,
   Author = {Chandrasekharan, S},
   Title = {Superconductivity and chiral symmetry breaking with fermion
             clusters},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {106-107},
   Pages = {1025-1027},
   Year = {2002},
   url = {http://arxiv.org/pdf/hep-lat/0110125},
   Abstract = {Cluster variables have recently revolutionized numerical
             work in certain models involving fermionic variables. This
             novel representation of fermionic partition functions is
             continuing to find new applications. After describing
             results from a study of a two dimensional Hubbard type model
             that confirm a superconducting transition in the
             Kosterlitz-Thouless universality class, we show how a
             cluster type algorithm can be devised to study the chiral
             limit of strongly coupled lattice gauge theories with
             staggered fermions.},
   Doi = {10.1016/S0920-5632(01)01917-X},
   Key = {Chandrasekharan:2001dd}
}

@article{fds245746,
   Author = {Brower, R and Chandrasekharan, S and Negele, JW and Wiese,
             U-J},
   Title = {Physical observables from lattice QCD at fixed
             topology},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {106-107},
   Pages = {581-583},
   Year = {2002},
   url = {http://dx.doi.org/10.1016/S0920-5632(01)01784-4},
   Abstract = {Because present Monte Carlo algorithms for lattice QCD may
             become trapped in a given topological charge sector when one
             approaches the continuum limit, it is important to
             understand the effect of calculating at fixed topology. In
             this work, we show that although the restriction to a fixed
             topological sector becomes irrelevant in the infinite volume
             limit, it gives rise to characteristic finite size effects
             due to contributions from all θ-vacua. We calculate these
             effects and show how to extract physical results from
             numerical data obtained at fixed topology.},
   Doi = {10.1016/S0920-5632(01)01784-4},
   Key = {fds245746}
}

@article{fds245747,
   Author = {Chandrasekharan, S and Scarlet, B and Wiese, U-J},
   Title = {From spin ladders to the 2D O(3) model at non-zero
             density},
   Journal = {Computer Physics Communications},
   Volume = {147},
   Number = {1-2},
   Pages = {388-393},
   Year = {2002},
   url = {http://dx.doi.org/10.1016/S0010-4655(02)00311-9},
   Abstract = {The numerical simulation of various field theories at
             non-zero chemical potential suffers from severe complex
             action problems. In particular, QCD at non-zero quark
             density can presently not be simulated for that reason. A
             similar complex action problem arises in the 2D O(3) model -
             a toy model for QCD. Here we construct the 2D O(3) model at
             non-zero density via dimensional reduction of an
             antiferromagnetic quantum spin ladder in a magnetic field.
             The complex action problem of the 2D O(3) model manifests
             itself as a sign problem of the ladder system. This sign
             problem is solved completely with a meron cluster algorithm.
             © 2002 Elsevier Science B.V. All rights
             reserved.},
   Doi = {10.1016/S0010-4655(02)00311-9},
   Key = {fds245747}
}

@article{fds245748,
   Author = {Chandrasekharan, S},
   Title = {Unexpected results in the chiral limit with staggered
             fermions},
   Journal = {Physics Letters B},
   Volume = {536},
   Number = {1-2},
   Pages = {72-78},
   Year = {2002},
   ISSN = {0370-2693},
   url = {http://dx.doi.org/10.1016/S0370-2693(02)01816-6},
   Abstract = {A cluster algorithm is constructed and applied to study the
             chiral limit of the strongly coupled lattice Schwinger model
             involving staggered fermions. The algorithm is based on a
             novel loop representation of the model. Finite size scaling
             of the chiral susceptibility based on data from lattices of
             size up to 64 × 64 indicates the absence of long range
             correlations at strong couplings. Assuming that there is no
             phase transition at a weaker coupling, the results imply
             that all mesons acquire a mass at non-zero lattice spacings.
             Although this does not violate any known physics, it is
             surprising since typically one expects a single pion to
             remain massless at non-zero lattice spacings in the
             staggered fermion formulation. © 2002 Elsevier Science B.V.
             All rights reserved.},
   Doi = {10.1016/S0370-2693(02)01816-6},
   Key = {fds245748}
}

@article{fds303645,
   Author = {Chandrasekharan, S},
   Title = {Novel Quantum Monte Carlo Algorithms for
             Fermions},
   Year = {2001},
   Month = {October},
   url = {http://arxiv.org/abs/hep-lat/0110018v1},
   Abstract = {Recent research shows that the partition function for a
             class of models involving fermions can be written as a
             statistical mechanics of clusters with positive definite
             weights. This new representation of the model allows one to
             construct novel algorithms. We illustrate this through
             models consisting of fermions with and without spin. A
             Hubbard type model with both attractive and repulsive
             interactions becomes tractable using the new approach.
             Precision results in the two dimensional attractive model
             confirm a superfluid phase transition in the
             Kosterlitz-Thouless universality class.},
   Key = {fds303645}
}

@article{fds303656,
   Author = {Chandrasekharan, S and Osborn, JC},
   Title = {Kosterlitz-Thouless Universality in a Fermionic
             System},
   Volume = {66},
   Pages = {045113},
   Year = {2001},
   Month = {September},
   url = {http://arxiv.org/abs/cond-mat/0109424v1},
   Abstract = {A new extension of the attractive Hubbard model is
             constructed to study the critical behavior near a finite
             temperature superconducting phase transition in two
             dimensions using the recently developed meron-cluster
             algorithm. Unlike previous calculations in the attractive
             Hubbard model which were limited to small lattices, the new
             algorithm is used to study the critical behavior on lattices
             as large as $128\times 128$. These precise results for the
             first time show that a fermionic system can undergo a finite
             temperature phase transition whose critical behavior is well
             described by the predictions of Kosterlitz and Thouless
             almost three decades ago. In particular it is confirmed that
             the spatial winding number susceptibility obeys the well
             known predictions of finite size scaling for $T<T_c$ and up
             to logarithmic corrections the pair susceptibility scales as
             $L^{2-\eta}$ at large volumes with $0\leq\eta\leq 0.25$ for
             $0\leq T\leq T_c$.},
   Doi = {10.1103/PhysRevB.66.045113},
   Key = {fds303656}
}

@article{Alford:2001ug,
   Author = {Alford, Mark G. and Chandrasekharan, S. and Cox, J. and Wiese, U. J.},
   Title = {Solution of the complex action problem in the Potts model
             for dense QCD},
   Journal = {Nucl. Phys. B},
   Volume = {602},
   Pages = {61-86},
   Year = {2001},
   url = {http://arxiv.org/pdf/hep-lat/0101012},
   Abstract = {http://arxiv.org/abs/hep-lat/0101012},
   Key = {Alford:2001ug}
}

@article{Chandrasekharan:2001cj,
   Author = {Chandrasekharan, Shailesh},
   Title = {Novel quantum Monte Carlo algorithms for
             fermions},
   Year = {2001},
   url = {http://arxiv.org/pdf/hep-lat/0110018},
   Abstract = {http://arxiv.org/abs/hep-lat/0110018},
   Key = {Chandrasekharan:2001cj}
}

@article{Chandrasekharan:2000fd,
   Author = {Chandrasekharan, S. and Chudnovsky, V. and Schlittgen, B. and Wiese, U. J.},
   Title = {Flop transitions in cuprate and color superconductors: From
             SO(5) to SO(10) unification?},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {94},
   Pages = {449-452},
   Year = {2001},
   url = {http://arxiv.org/pdf/hep-lat/0011054},
   Abstract = {http://arxiv.org/abs/hep-lat/0011054},
   Key = {Chandrasekharan:2000fd}
}

@article{Chandrasekharan:2000ew,
   Author = {Chandrasekharan, Shailesh},
   Title = {QCD at a finite density of static quarks},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {94},
   Pages = {71-78},
   Year = {2001},
   url = {http://arxiv.org/pdf/hep-lat/0011022},
   Abstract = {http://arxiv.org/abs/hep-lat/0011022},
   Key = {Chandrasekharan:2000ew}
}

@book{fds4128,
   Author = {S. Chandrasekharan},
   Title = {NOVEL QUANTUM MONTE CARLO ALGORITHMS FOR
             FERMIONS},
   Booktitle = {Quantum Monte Carlo: Recent Advances and Common Problems in
             Condensed Matter Physics and Field Theory},
   Publisher = {EDIZIONI ETS},
   Editor = {M. Compostrini and M.P. Lomardo and F. Paderiva},
   Year = {2001},
   Abstract = {Recent research shows that the partition function for a
             class of models involving fermions can be written as a
             statistical mechanics of clusters with positive definite
             weights. This new representation of the model allows one to
             construct novel algorithms. We illustrate this through
             models consisting of fermions with and without spin. A
             Hubbard type model with both attractive and repulsive
             interactions becomes tractable using the new approach.
             Precision results in the two dimensional attractive model
             confirm a superfluid phase transition in the
             Kosterlitz-Thouless universality class.},
   Key = {fds4128}
}

@article{Chandrasekharan:2000fr,
   Author = {Chandrasekharan, S and Osborn, J},
   Title = {Solving sign problems with meron algorithms},
   Journal = {Springer Proceedings in Physics},
   Volume = {86},
   Pages = {28-42},
   Year = {2001},
   ISSN = {0930-8989},
   url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000165950700004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
   Key = {Chandrasekharan:2000fr}
}

@article{fds245743,
   Author = {Chandrasekharan, S},
   Title = {QCD at a finite density of static quarks},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {94},
   Number = {1-3},
   Pages = {71-78},
   Year = {2001},
   url = {http://dx.doi.org/10.1016/S0920-5632(01)00936-7},
   Abstract = {Recently, cluster methods have been used to solve a variety
             of sign problems including those that arise in the presence
             of fermions. In all cases an analytic partial re-summation
             over a class of configurations in the path integral was
             necessary. Here the new ideas are illustrated using the
             example of QCD at a finite density of static quarks. In this
             limit the sign problem simplifies since the fermionic part
             decouples. Furthermore, the problem can be solved completely
             when the gauge dynamics is replaced by a Potts model. On the
             other hand in QCD with light quarks the solution will
             require a partial re-summation over both fermionic and gauge
             degrees of freedom. The new approach points to unexplored
             directions in the search for a solution to this more
             challenging sign problem. © 2001 Elsevier Science B.V. All
             rights reserved.},
   Doi = {10.1016/S0920-5632(01)00936-7},
   Key = {fds245743}
}

@article{fds245744,
   Author = {Alford, M and Chandrasekharan, S and Cox, J and Wiese,
             U-J},
   Title = {Solution of the complex action problem in the Potts model
             for dense QCD},
   Journal = {Nuclear Physics B},
   Volume = {602},
   Number = {1-2},
   Pages = {61-86},
   Year = {2001},
   url = {http://dx.doi.org/10.1016/S0550-3213(01)00068-2},
   Abstract = {Monte Carlo simulations of lattice QCD at non-zero baryon
             chemical potential μ suffer from the notorious complex
             action problem. We consider QCD with static quarks coupled
             to a large chemical potential. This leaves us with an SU(3)
             Yang-Mills theory with a complex action containing the
             Polyakov loop. Close to the deconfinement phase transition
             the qualitative features of this theory, in particular its
             Z(3) symmetry properties, are captured by the 3-d 3-state
             Potts model. We solve the complex action problem in the
             Potts model by using a cluster algorithm. The improved
             estimator for the μ-dependent part of the Boltzmann factor
             is real and positive and is used for importance sampling. We
             localize the critical endpoint of the first order
             deconfinement phase transition line and find consistency
             with universal 3-d Ising behavior. We also calculate the
             static quark-quark, quark-antiquark, and antiquark-antiquark
             potentials which show screening as expected for a system
             with non-zero baryon density.},
   Doi = {10.1016/S0550-3213(01)00068-2},
   Key = {fds245744}
}

@article{fds245745,
   Author = {Chandrasekharan, S and Chudnovsky, V and Schlittgen, B and Wiese,
             U-J},
   Title = {Flop transitions in cuprate and color superconductors: From
             SO(5) to SO(10) unification?},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {94},
   Number = {1-3},
   Pages = {449-452},
   Year = {2001},
   url = {http://dx.doi.org/10.1016/S0920-5632(01)01002-7},
   Abstract = {The phase diagrams of cuprate superconductors and of QCD at
             non-zero baryon chemical potential are qualitatively
             similar. The Néel phase of the cuprates corresponds to the
             chirally broken phase of QCD, and the high-temperature
             superconducting phase corresponds to the color
             superconducting phase. In the SO(5) theory for the cuprates
             the SO(3)s spin rotational symmetry and the U(1)em gauge
             symmetry of electromagnetism are dynamically unified. This
             suggests that the SU(2)L ⊗ SU(2)R ⊗ U(1)B chiral
             symmetry of QCD and the SU(3)c color gauge symmetry may get
             unified to SO(10). Dynamical enhancement of symmetry from
             SO(2)s ⊗ Z(2) to SO(3)s is known to occur in anisotropic
             antiferromagnets. In these systems the staggered
             magnetization flops from an easy 3-axis into the 12-plane at
             a critical value of the external magnetic field. Similarly,
             the phase transitions in the SO(5) and SO(10) models are
             flop transitions of a "superspin". Despite this fact, a
             renormalization group flow analysis in 4 - ε dimensions
             indicates that a point with full SO(5) or SO(10) symmetry
             exists neither in the cuprates nor in QCD. © 2001 Elsevier
             Science B.V. All rights reserved.},
   Doi = {10.1016/S0920-5632(01)01002-7},
   Key = {fds245745}
}

@article{fds303644,
   Author = {Chandrasekharan, S and Wiese, U-J},
   Title = {SO(10) Unification of Color Superconductivity and Chiral
             Symmetry Breaking?},
   Year = {2000},
   Month = {March},
   url = {http://arxiv.org/abs/hep-ph/0003214v1},
   Abstract = {Motivated by the SO(5) theory of high-temperature
             superconductivity and antiferromagnetism, we ask if an
             SO(10) theory unifies color superconductivity and chiral
             symmetry breaking in QCD. The transition to the color
             superconducting phase would then be analogous to a spin flop
             transition. While the spin flop transition generically has a
             unified SO(3) description, the SO(5) and SO(10) symmetric
             fixed points are unstable, at least in (4 - epsilon)
             dimensions, and require the fine-tuning of one additional
             relevant parameter. If QCD is near the SO(10) fixed point,
             it has interesting consequences for heavy ion collisions and
             neutron stars.},
   Key = {fds303644}
}

@book{fds4130,
   Author = {S. Chandrasekharan},
   Title = {SOLVING SIGN PROBLEMS WITH MERON ALGORITHMS},
   Series = {Springer Proc. Phys. 86, pp 28-42},
   Booktitle = {Computer Simulations in Condensed Matter Physics
             XIII},
   Publisher = {Springer},
   Editor = {D.P. Landau and S.P.Lewis and H.-B.Shuttler},
   Year = {2000},
   Month = {January},
   Key = {fds4130}
}

@article{Chandrasekharan:2000dj,
   Author = {Chandrasekharan, S},
   Title = {A Chiral Phase Transition using a Fermion Cluster
             Algorithm},
   Journal = {Chin.J.Phys.},
   Volume = {38},
   Pages = {696-706},
   Year = {2000},
   Month = {January},
   url = {http://arxiv.org/abs/hep-lat/0001003v1},
   Abstract = {The recent solution to the fermion sign problem allows, for
             the first time, the use of cluster algorithm techniques to
             compute certain fermionic path integrals. To illustrate the
             underlying ideas behind the progress, a cluster algorithm is
             constructed to study the chiral phase transition in a
             strongly interacting staggered fermion model with an
             arbitrary mass term in 3+1 dimensions. Unlike conventional
             methods there is no difficulty in the cluster method to
             approach the chiral (massless) limit. Results using the new
             algorithm confirm that the chiral transition falls under the
             expected universality class.},
   Key = {Chandrasekharan:2000dj}
}

@article{Chandrasekharan:1999ys,
   Author = {Chandrasekharan, S. and Cox, J. and Holland, K. and Wiese,
             U. J.},
   Title = {Meron-cluster simulation of a chiral phase transition with
             staggered fermions},
   Journal = {Nucl. Phys. B},
   Volume = {576},
   Pages = {481-500},
   Year = {2000},
   url = {http://arxiv.org/pdf/hep-lat/9906021},
   Abstract = {http://arxiv.org/abs/hep-lat/9906021},
   Key = {Chandrasekharan:1999ys}
}

@article{Chandrasekharan:2000gk,
   Author = {Chandrasekharan, Shailesh and Wiese, Uwe-Jens},
   Title = {SO(10) unification of color superconductivity and chiral
             symmetry breaking?},
   Year = {2000},
   url = {http://arxiv.org/pdf/hep-ph/0003214},
   Abstract = {http://arxiv.org/abs/hep-ph/0003214},
   Key = {Chandrasekharan:2000gk}
}

@article{Chandrasekharan:2000rm,
   Author = {Chandrasekharan, Shailesh and Osborn, James
             C.},
   Title = {Critical behavior of a chiral condensate with a meron
             cluster algorithm},
   Journal = {Phys. Lett. B},
   Volume = {496},
   Pages = {122-128},
   Year = {2000},
   url = {http://arxiv.org/pdf/hep-lat/0010036},
   Abstract = {http://arxiv.org/abs/hep-lat/0010036},
   Key = {Chandrasekharan:2000rm}
}

@article{fds4134,
   Author = {S. Chandrasekharan and U.-J. Wiese},
   Title = {SO(10) UNIFICATION OF COLOR SUPERCONDUCTIVITY AND CHIRAL
             SYMMETRY BREAKING?},
   Year = {2000},
   Abstract = {Motivated by the SO(5) theory of high-temperature
             superconductivity and antiferromagnetism, we ask if an
             SO(10) theory unifies color superconductivity and chiral
             symmetry breaking in QCD. The transition to the color
             superconducting phase would then be analogous to a spin flop
             transition. While the spin flop transition generically has a
             unified SO(3) description, the SO(5) and SO(10) symmetric
             fixed points are unstable, at least in (4 - epsilon)
             dimensions, and require the fine-tuning of one additional
             relevant parameter. If QCD is near the SO(10) fixed point,
             it has interesting consequences for heavy ion collisions and
             neutron stars.},
   Key = {fds4134}
}

@article{Chandrasekharan:1999vz,
   Author = {Chandrasekharan, S},
   Title = {Fermion cluster algorithms},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {83-84},
   Number = {1-3},
   Pages = {774-776},
   Year = {2000},
   url = {http://arxiv.org/pdf/hep-lat/9909007},
   Abstract = {Cluster algorithms have been recently used to eliminate sign
             problems that plague Monte-Carlo methods in a variety of
             systems. In particular such algorithms can also be used to
             solve sign problems associated with the permutation of
             fermion world lines. This solution leads to the possibility
             of designing fermion cluster algorithms in certain cases.
             Using the example of free non-relativistic fermions we
             discuss the ideas underlying the algorithm.},
   Key = {Chandrasekharan:1999vz}
}

@article{fds245740,
   Author = {Chandrasekharan, S and Cox, J and Holland, K and Wiese,
             U-J},
   Title = {Meron-cluster simulation of a chiral phase transition with
             staggered fermions},
   Journal = {Nuclear Physics B},
   Volume = {576},
   Number = {1-3},
   Pages = {481-500},
   Year = {2000},
   Abstract = {We examine a (3 + 1)-dimensional model of staggered lattice
             fermions with a four-fermion interaction and ℤ(2) chiral
             symmetry using the Hamiltonian formulation. This model
             cannot be simulated with standard fermion algorithms because
             those suffer from a very severe sign problem. We use a new
             fermion simulation technique - the meron-cluster algorithm -
             which solves the sign problem and leads to high-precision
             numerical data. We investigate the finite temperature chiral
             phase transition and verify that it is in the universality
             class of the 3-d Ising model using finite-size scaling. ©
             2000 Elsevier Science B.V. All rights reserved.},
   Key = {fds245740}
}

@article{fds245742,
   Author = {Chandrasekharan, S and Osborn, JC},
   Title = {Critical behavior of a chiral condensate with a meron
             cluster algorithm},
   Journal = {Physics Letters B},
   Volume = {496},
   Number = {1-2},
   Pages = {122-128},
   Year = {2000},
   ISSN = {0370-2693},
   url = {http://dx.doi.org/10.1016/S0370-2693(00)01294-6},
   Abstract = {A new meron cluster algorithm is constructed to study the
             finite temperature critical behavior of the chiral
             condensate in a (3 + 1)-dimensional model of interacting
             staggered fermions. Using finite size scaling analysis the
             infinite volume condensate is shown to be consistent with
             the behavior of the form (Tc - T)0.314(7) for temperatures
             less than the critical temperature and m1/4.87(10) at the
             critical temperature confirming that the critical behavior
             belongs to the 3-d Ising universality class within one to
             two sigma deviation. The new method, along with improvements
             in the implementation of the algorithm, allows the
             determination of the critical temperature Tc more accurately
             than was possible in a previous study. © 2000 Elsevier
             Science B.V.},
   Doi = {10.1016/S0370-2693(00)01294-6},
   Key = {fds245742}
}

@article{fds303642,
   Author = {Chandrasekharan, S and Scarlet, B and Wiese, U-J},
   Title = {Meron-Cluster Simulation of Quantum Spin Ladders in a
             Magnetic Field},
   Year = {1999},
   Month = {September},
   url = {http://arxiv.org/abs/cond-mat/9909451v1},
   Abstract = {Numerical simulations of numerous quantum systems suffer
             from the notorious sign problem. Meron-cluster algorithms
             lead to an efficient solution of sign problems for both
             fermionic and bosonic models. Here we apply the meron
             concept to quantum spin systems in an arbitrary external
             magnetic field, in which case standard cluster algorithms
             fail. As an example, we simulate antiferromagnetic quantum
             spin ladders in a uniform external magnetic field that
             competes with the spin-spin interaction. The numerical
             results are in agreement with analytic predictions for the
             magnetization as a function of the external
             field.},
   Key = {fds303642}
}

@article{Chandrasekharan:1998wg,
   Author = {Chandrasekharan, Shailesh},
   Title = {Lattice QCD with Ginsparg-Wilson fermions},
   Journal = {Phys. Rev. D},
   Volume = {60},
   Pages = {074503},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9805015},
   Abstract = {http://arxiv.org/abs/hep-lat/9805015},
   Key = {Chandrasekharan:1998wg}
}

@article{Chandrasekharan:1999zt,
   Author = {Chandrasekharan, S. and Scarlet, B. and Wiese, U.
             J.},
   Title = {Meron-Cluster Simulation of Quantum Spin Ladders in a
             Magnetic Field},
   Year = {1999},
   url = {http://arxiv.org/pdf/cond-mat/9909451},
   Abstract = {http://arxiv.org/abs/cond-mat/9909451},
   Key = {Chandrasekharan:1999zt}
}

@article{Chandrasekharan:1999cm,
   Author = {Chandrasekharan, Shailesh and Wiese, Uwe-Jens},
   Title = {Meron-cluster solution of a fermion sign
             problem},
   Journal = {Phys. Rev. Lett.},
   Volume = {83},
   Pages = {3116-3119},
   Year = {1999},
   url = {http://arxiv.org/pdf/cond-mat/9902128},
   Abstract = {http://arxiv.org/abs/cond-mat/9902128},
   Key = {Chandrasekharan:1999cm}
}

@article{Chandrasekharan:1998yx,
   Author = {Chandrasekharan, Shailesh and others},
   Title = {Anomalous chiral symmetry breaking above the QCD phase
             transition},
   Journal = {Phys. Rev. Lett.},
   Volume = {82},
   Pages = {2463-2466},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9807018},
   Abstract = {http://arxiv.org/abs/hep-lat/9807018},
   Key = {Chandrasekharan:1998yx}
}

@article{Bhattacharya:1999uq,
   Author = {Bhattacharya, Tanmoy and Chandrasekharan, Shailesh and Gupta, Rajan and Lee, Weon-Jong and Sharpe, Stephen
             R.},
   Title = {Non-perturbative renormalization constants using Ward
             identities},
   Journal = {Phys. Lett. B},
   Volume = {461},
   Pages = {79-88},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9904011},
   Abstract = {http://arxiv.org/abs/hep-lat/9904011},
   Key = {Bhattacharya:1999uq}
}

@article{Chandrasekharan:1998ck,
   Author = {Chandrasekharan, Shailesh},
   Title = {Confinement, chiral symmetry breaking and continuum limits
             in quantum link models},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {73},
   Pages = {739-741},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9809084},
   Abstract = {http://arxiv.org/abs/hep-lat/9809084},
   Key = {Chandrasekharan:1998ck}
}

@article{fds4139,
   Author = {S. Chandrasekharan and B. Scarlet and U.-J.
             Wiese},
   Title = {MERON CLUSTER SIMULATION OF QUANTUM SPIN LADDERS IN A
             MAGNETIC FIELD},
   Year = {1999},
   Key = {fds4139}
}

@article{Chandrasekharan:1998em,
   Author = {Chandrasekharan, S},
   Title = {Ginsparg-Wilson fermions: A study in the Schwinger
             model},
   Journal = {Physical Review D - Particles, Fields, Gravitation and
             Cosmology},
   Volume = {59},
   Number = {9},
   Pages = {1-8},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9810007},
   Abstract = {The qualitative features of Ginsparg-Wilson fermions, as
             formulated by Neuberger, coupled to two-dimensional U(1)
             gauge theory are studied. The role of the Wilson mass
             parameter in changing the number of massless flavors in the
             theory and its connection with the index of the Dirac
             operator is studied. Although the index of the Dirac
             operator is not related to the geometric definition of the
             topological charge for strong couplings, the two start to
             agree as soon as one goes to moderately weak couplings. This
             produces the desired singularity in the quenched chiral
             condensate which appears to be very difficult to reproduce
             with staggered fermions. The fermion determinant removes the
             singularity and reproduces the known chiral condensate and
             the meson mass within understandable errors. ©1999 The
             American Physical Society.},
   Key = {Chandrasekharan:1998em}
}

@article{fds245673,
   Author = {Chandrasekharan, S},
   Title = {Lattice QCD with Ginsparg-Wilson fermions},
   Journal = {Physical Review D - Particles, Fields, Gravitation and
             Cosmology},
   Volume = {60},
   Number = {7},
   Pages = {1-6},
   Year = {1999},
   url = {http://arxiv.org/abs/hep-lat/9805015v3},
   Abstract = {Lattice QCD using fermions whose Dirac operator obeys the
             Ginsparg-Wilson relation is perhaps the best known
             formulation of QCD with a finite cutoff. It reproduces all
             the low energy QCD phenomenology associated with chiral
             symmetry at finite lattice spacings. In particular it
             explains the origin of massless pions due to spontaneous
             chiral symmetry breaking and leads to new ways to approach
             the U(1) problem on the lattice. Here we show these results
             in the path integral formulation and derive for the first
             time in lattice QCD a known formal continuum relation
             between the chiral condensate and the topological
             susceptibility. This relation leads to predictions for the
             critical behavior of the topological susceptibility near the
             phase transition and can now be checked in Monte Carlo
             simulations even at finite lattice spacings. ©1999 The
             American Physical Society.},
   Doi = {10.1103/PhysRevD.60.074503},
   Key = {fds245673}
}

@article{Brower:1997ha,
   Author = {Brower, R and Chandrasekharan, S and Wiese, U-J},
   Title = {QCD as a quantum link model},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {60},
   Number = {9},
   Pages = {DUMMY42},
   Year = {1999},
   ISSN = {0556-2821},
   url = {http://arxiv.org/pdf/hep-th/9704106},
   Abstract = {QCD is constructed as a lattice gauge theory in which the
             elements of the link matrices are represented by
             non-commuting operators acting in a Hubert space. The
             resulting quantum link model for QCD is formulated with a
             fifth Euclidean dimension, whose extent resembles the
             inverse gauge coupling of the resulting fourdimensional
             theory after dimensional reduction. The inclusion of quarks
             is natural in Shamir's variant of Kaplan's fermion method,
             which does not require fine-tuning to approach the chiral
             limit. A rishon representation in terms of fermionic
             constituents of the gluons is derived and the quantum link
             Hamiltonian for QCD with a U(N) gauge symmetry is expressed
             in terms of glueball, meson and constituent quark operators.
             The new formulation of QCD is promising both from an
             analytic and from a computational point of view. ©1999 The
             American Physical Society.},
   Key = {Brower:1997ha}
}

@article{Bhattacharya:1998ue,
   Author = {Bhattacharya, T and Chandrasekharan, S and Gupta, R and Lee, W and Sharpe, S},
   Title = {Non-perturbative renormalization constants using Ward
             identities},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {73},
   Number = {1-3},
   Pages = {276-278},
   Year = {1999},
   url = {http://arxiv.org/pdf/hep-lat/9810018},
   Abstract = {We extend the application of vector and axial Ward
             identities to calculate bA, bP and bT, coefficients that
             give the mass dependence of the renormalization constants of
             the corresponding bilinear operators in the quenched theory.
             The extension relies on using operators with non-degenerate
             quark masses. It allows a complete determination of the O(a)
             improvement coefficients for bilinears in the quenched
             approximation using Ward Identities alone. Only the scale
             dependent normalization constants Z0P (or Z0S) and ZT are
             undetermined. We present results of a pilot numerical study
             using hadronic correlators.},
   Key = {Bhattacharya:1998ue}
}

@article{fds245736,
   Author = {Bhattacharya, T and Chandrasekharan, S and Gupta, R and Lee, W and Sharpe, S},
   Title = {Non-perturbative renormalization constants using Ward
             identities 1},
   Journal = {Physics Letters, Section B: Nuclear, Elementary Particle and
             High-Energy Physics},
   Volume = {461},
   Number = {1-2},
   Pages = {79-88},
   Year = {1999},
   Abstract = {We extend the application of axial Ward identities to
             calculate bA, bp and bT, coefficients that give the mass
             dependence of the renormalization constants of the
             corresponding bilinear operators in the quenched theory. The
             extension relies on using operators with non-degenerate
             quark masses. It allows a complete determination of the O(a)
             improvement coefficients for bilinears in the quenched
             approximation using Ward Identities alone. Only the scale
             dependent normalization constants ZP0 (or ZS0) and ZT are
             undetermined. We present results of a pilot numerical study
             using hadronic correlators. © 1999 Elsevier Science B.V.
             All rights reserved.},
   Key = {fds245736}
}

@article{fds245738,
   Author = {Chandrasekharan, S},
   Title = {Confinement, chiral symmetry breaking and continuum limits
             in quantum link models},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {73},
   Number = {1-3},
   Pages = {739-741},
   Year = {1999},
   Abstract = {Using the example of compact U(1) lattice gauge theory we
             argue that quantum link models can be used to reproduce the
             physics of conventional Hamiltonian lattice gauge theories.
             In addition to the usual gauge coupling g, these models have
             a new parameter j which naturally cuts-off large electric
             flux quanta on each link while preserving exact U(1) gauge
             invariance. The j → ∞ limit recovers the conventional
             Hamiltonian. At strong couplings, the theory shows
             confinement and chiral symmetry breaking for all non-trivial
             values of j. The phase diagram of the 3+1 dimensional theory
             suggests that a coulomb phase is present at large but finite
             j. Setting g = 0, a new approach to the physics of compact
             U(1) gauge theory on the lattice emerges. In this case the
             parameter j takes over the role of the gauge coupling, and j
             → ∞ describes free photons.},
   Key = {fds245738}
}

@article{fds245739,
   Author = {Chandrasekharan, S and Chen, D and Christ, N and Lee, W and Mawhinney,
             R and Vranas, P},
   Title = {Anomalous chiral symmetry breaking above the QCD phase
             transition},
   Journal = {Physical Review Letters},
   Volume = {82},
   Number = {12},
   Pages = {2463-2466},
   Year = {1999},
   Abstract = {We study the anomalous breaking of UA(1) symmetry just above
             the QCD phase transition for zero and two flavors of quarks,
             using a staggered fermion, lattice discretization. The
             properties of the QCD phase transition are expected to
             depend on the degree of UA(1) symmetry breaking in the
             transition region. For the physical case of two flavors, we
             carry out extensive simulations on a 163 × 4 lattice,
             measuring a difference in susceptibilities which is
             sensitive to UA(1) symmetry and which avoids many of the
             staggered fermion discretization difficulties. The results
             suggest that anomalous effects are at or below the 15%
             level. © 1999 The American Physical Society.},
   Key = {fds245739}
}

@article{fds245741,
   Author = {Chandrasekharan, S and Wiese, U-J},
   Title = {Meron-Cluster Solution of Fermion Sign Problems},
   Journal = {Physical Review Letters},
   Volume = {83},
   Number = {16},
   Pages = {3116-3119},
   Year = {1999},
   Abstract = {We present a general strategy to solve the notorious fermion
             sign problem using cluster algorithms. The method applies to
             various systems in the Hubbard model family as well as to
             relativistic fermions. Here it is illustrated for
             nonrelativistic lattice fermions. A configuration of fermion
             world lines is decomposed into clusters that contribute
             independently to the fermion permutation sign. A cluster
             whose flip changes the sign is referred to as a meron.
             Configurations containing meron clusters contribute 0 to the
             path integral, while all other configurations contribute 1.
             The cluster representation describes the partition function
             as a gas of clusters in the zero-meron sector.},
   Key = {fds245741}
}

@article{fds303655,
   Author = {Chandrasekharan, S},
   Title = {Ginsparg-Wilson Fermions: A study in the Schwinger
             Model},
   Journal = {Phys.Rev. D},
   Volume = {59},
   Pages = {094502},
   Year = {1998},
   Month = {October},
   url = {http://arxiv.org/abs/hep-lat/9810007v2},
   Abstract = {Qualitative features of Ginsparg-Wilson fermions, as
             formulated by Neuberger, coupled to two dimensional U(1)
             gauge theory are studied. The role of the Wilson mass
             parameter in changing the number of massless flavors in the
             theory and its connection with the index of the Dirac
             operator is studied. Although the index of the Dirac
             operator is not related to the geometric definition of the
             topological charge for strong couplings, the two start to
             agree as soon as one goes to moderately weak couplings. This
             produces the desired singularity in the quenched chiral
             condensate which appears to be very difficult to reproduce
             with staggered fermions. The fermion determinant removes the
             singularity and reproduces the known chiral condensate and
             the meson mass within understandable errors.},
   Doi = {10.1103/PhysRevD.59.094502},
   Key = {fds303655}
}

@article{Beard:1997ic,
   Author = {Beard, B. B. and others},
   Title = {D-theory: Field theory via dimensional reduction of discrete
             variables},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {63},
   Pages = {775-789},
   Year = {1998},
   url = {http://arxiv.org/pdf/hep-lat/9709120},
   Abstract = {http://arxiv.org/abs/hep-lat/9709120},
   Key = {Beard:1997ic}
}

@article{Brower:1998kg,
   Author = {Brower, R. and Chandrasekharan, S. and Wiese, U.
             J.},
   Title = {Green's functions from quantum cluster algorithms},
   Journal = {Physica A},
   Volume = {261},
   Pages = {520},
   Year = {1998},
   url = {http://arxiv.org/pdf/cond-mat/9801003},
   Abstract = {http://arxiv.org/abs/cond-mat/9801003},
   Key = {Brower:1998kg}
}

@article{Orginos:1997fh,
   Author = {Orginos, K. and Bietenholz, W. and Brower, R. and Chandrasekharan, S. and Wiese, U. -J.},
   Title = {The perfect quark-gluon vertex function},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {63},
   Pages = {904-906},
   Year = {1998},
   url = {http://arxiv.org/pdf/hep-lat/9709100},
   Abstract = {http://arxiv.org/abs/hep-lat/9709100},
   Key = {Orginos:1997fh}
}

@article{fds245666,
   Author = {Brower, R and Chandrasekharan, S and Wiese, U-J},
   Title = {Green’s functions from quantum cluster algorithms11This
             work is supported in part by funds provided by the US
             Department of Energy (DOE) under cooperative research
             agreement DE-FC02-94ER40818.},
   Volume = {261},
   Number = {3},
   Pages = {520-533},
   Year = {1998},
   Abstract = {We show that cluster algorithms for quantum models have a
             meaning independent of the basis chosen to construct them.
             Using this idea, we propose a new method for measuring with
             little effort a whole class of Green’s functions, once a
             cluster algorithm for the partition function has been
             constructed. To explain the idea, we consider the quantum XY
             model and compute its two point Green’s function in
             various ways, showing that all of them are equivalent. We
             also provide numerical evidence confirming the analytic
             arguments. Similar techniques are applicable to other
             models. In particular, in the recently constructed quantum
             link models, the new technique allows us to construct
             improved estimators for Wilson loops and may lead to a very
             precise determination of the glueball spectrum.},
   Key = {fds245666}
}

@article{fds245724,
   Author = {Beard, BB and Brower, RC and Chandrasekharan, S and Chen, D and Tsapalis, A and Wiese, U-J},
   Title = {D-theory: Field theory via dimensional reduction of discrete
             variables},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {63},
   Number = {1-3},
   Pages = {775-789},
   Year = {1998},
   Abstract = {A new non-perturbative approach to quantum field theory -
             D-theory - is proposed, in which continuous classical fields
             are replaced by discrete quantized variables which undergo
             dimensional reduction. The 2-d classical O(3) model emerges
             from the (2 + 1)-d quantum Heisenberg model formulated in
             terms of quantum spins. Dimensional reduction is
             demonstrated explicitly by simulating correlation lengths up
             to 350,000 lattice spacings using a loop cluster algorithm.
             In the framework of D-theory, gauge theories are formulated
             in terms of quantum links - the gauge analogs of quantum
             spins. Quantum links are parallel transporter matrices whose
             elements are non-commuting operators. They can be expressed
             as bilinears of anticommuting fermion constituents. In
             quantum link models dimensional reduction to four dimensions
             occurs, due to the presence of a 5-d Coulomb phase, whose
             existence is confirmed by detailed simulations using
             standard lattice gauge theory. Using Shamir's variant of
             Kaplan's fermion proposal, in quantum link QCD quarks appear
             as edge states of a 5-d slab. This naturally protects their
             chiral symmetries without fine-tuning. The first efficient
             cluster algorithm for a gauge theory with a continuous gauge
             group is formulated for the U(1) quantum link model.
             Improved estimators for Wilson loops are constructed, and
             dimensional reduction to ordinary lattice QED is verified
             numerically.},
   Key = {fds245724}
}

@article{fds245725,
   Author = {Orginos, K and Bietenholz, W and Brower, R and Chandrasekharan, S and Wiese, U-J},
   Title = {The perfect Quark-Gluon vertex function},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {63},
   Number = {1-3},
   Pages = {904-906},
   Year = {1998},
   Abstract = {We evaluate a perfect quark-gluon vertex function for QCD in
             coordinate space and truncate it to a short range. We
             present preliminary results for the charmonium spectrum
             using this quasi-perfect action.},
   Key = {fds245725}
}

@article{fds245737,
   Author = {Brower, R and Chandrasekharan, S and Wiese, U-J},
   Title = {Green's functions from quantum cluster algorithms},
   Journal = {Physica A: Statistical Mechanics and its
             Applications},
   Volume = {261},
   Number = {3-4},
   Pages = {520-533},
   Year = {1998},
   Abstract = {We show that cluster algorithms for quantum models have a
             meaning independent of the basis chosen to construct them.
             Using this idea, we propose a new method for measuring with
             little effort a whole class of Green's functions, once a
             cluster algorithm for the partition function has been
             constructed. To explain the idea, we consider the quantum XY
             model and compute its two point Green's function in various
             ways, showing that all of them are equivalent. We also
             provide numerical evidence confirming the analytic
             arguments. Similar techniques are applicable to other
             models. In particular, in the recently constructed quantum
             link models, the new technique allows us to construct
             improved estimators for Wilson loops and may lead to a very
             precise determination of the glueball spectrum. © 1998
             Published by Elsevier Science B.V. All rights
             reserved.},
   Key = {fds245737}
}

@article{fds303654,
   Author = {Brower, R and Chandrasekharan, S and Wiese, U-J},
   Title = {QCD as a Quantum Link Model},
   Journal = {Phys. Rev. D},
   Volume = {60},
   Pages = {094502},
   Year = {1997},
   Month = {April},
   url = {http://arxiv.org/abs/hep-th/9704106v1},
   Abstract = {QCD is constructed as a lattice gauge theory in which the
             elements of the link matrices are represented by
             non-commuting operators acting in a Hilbert space. The
             resulting quantum link model for QCD is formulated with a
             fifth Euclidean dimension, whose extent resembles the
             inverse gauge coupling of the resulting four-dimensional
             theory after dimensional reduction. The inclusion of quarks
             is natural in Shamir's variant of Kaplan's fermion method,
             which does not require fine-tuning to approach the chiral
             limit. A rishon representation in terms of fermionic
             constituents of the gluons is derived and the quantum link
             Hamiltonian for QCD with a U(N) gauge symmetry is expressed
             in terms of glueball, meson and constituent quark operators.
             The new formulation of QCD is promising both from an
             analytic and from a computational point of
             view.},
   Doi = {10.1103/PhysRevD.60.094502},
   Key = {fds303654}
}

@article{Bietenholz:1997kr,
   Author = {Bietenholz, W. and Brower, R. and Chandrasekharan, S. and Wiese, U. J.},
   Title = {Perfect lattice topology: The quantum rotor as a test
             case},
   Journal = {Phys. Lett. B},
   Volume = {407},
   Pages = {283-289},
   Year = {1997},
   url = {http://arxiv.org/pdf/hep-lat/9704015},
   Abstract = {http://arxiv.org/abs/hep-lat/9704015},
   Key = {Bietenholz:1997kr}
}

@article{Bietenholz:1996qc,
   Author = {Bietenholz, W. and Brower, R. and Chandrasekharan, S. and Wiese, U. J.},
   Title = {Perfect lattice actions for staggered fermions},
   Journal = {Nucl. Phys. B},
   Volume = {495},
   Pages = {285-305},
   Year = {1997},
   url = {http://arxiv.org/pdf/hep-lat/9612007},
   Abstract = {http://arxiv.org/abs/hep-lat/9612007},
   Key = {Bietenholz:1996qc}
}

@article{Chandrasekharan:1996ih,
   Author = {Chandrasekharan, S. and Wiese, U. J.},
   Title = {Quantum link models: A discrete approach to gauge
             theories},
   Journal = {Nucl. Phys. B},
   Volume = {492},
   Pages = {455-474},
   Year = {1997},
   url = {http://arxiv.org/pdf/hep-lat/9609042},
   Abstract = {http://arxiv.org/abs/hep-lat/9609042},
   Key = {Chandrasekharan:1996ih}
}

@article{Bietenholz:1996pf,
   Author = {Bietenholz, W. and Brower, R. and Chandrasekharan, S. and Wiese, U. J.},
   Title = {Progress on perfect lattice actions for QCD},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {53},
   Pages = {921-934},
   Year = {1997},
   url = {http://arxiv.org/pdf/hep-lat/9608068},
   Abstract = {http://arxiv.org/abs/hep-lat/9608068},
   Key = {Bietenholz:1996pf}
}

@article{Chandrasekharan:1996en,
   Author = {Chandrasekharan, Shailesh},
   Title = {A large N chiral transition on a plaquette},
   Journal = {Phys. Lett. B},
   Volume = {395},
   Pages = {83-88},
   Year = {1997},
   url = {http://arxiv.org/pdf/hep-th/9610225},
   Abstract = {http://arxiv.org/abs/hep-th/9610225},
   Key = {Chandrasekharan:1996en}
}

@article{fds245726,
   Author = {Bietenholz, W and Brower, R and Chandrasekharan, S and Wiese,
             U-J},
   Title = {Perfect lattice topology: The quantum rotor as a test
             case},
   Journal = {Physics Letters, Section B: Nuclear, Elementary Particle and
             High-Energy Physics},
   Volume = {407},
   Number = {3-4},
   Pages = {283-289},
   Year = {1997},
   Abstract = {Lattice actions and topological charges that are classically
             and quantum mechanically perfect (i.e. free of lattice
             artifacts) are constructed analytically for the quantum
             rotor. It is demonstrated that the Manton action is
             classically perfect while the Villain action is quantum
             perfect. The geometric construction for the topological
             charge is only perfect at the classical level. The quantum
             perfect lattice topology associates a topological charge
             distribution, not just a single charge, with each lattice
             field configuration. For the quantum rotor with the
             classically perfect action and topological charge, the
             remaining cut-off effects are exponentially suppressed. ©
             1997 Published by Elsevier Science B.V.},
   Key = {fds245726}
}

@article{fds245727,
   Author = {Bietenholz, W and Brower, R and Chandrasekharan, S and Wiese,
             U-J},
   Title = {Perfect lattice actions for staggered fermions},
   Journal = {Nuclear Physics B},
   Volume = {495},
   Number = {1-2},
   Pages = {285-305},
   Year = {1997},
   Abstract = {We construct a perfect lattice action for staggered fermions
             by blocking from the continuum. The locality, spectrum and
             pressure of such perfect staggered fermions are discussed.
             We also derive a consistent fixed point action for free
             gauge fields and discuss its locality as well as the
             resulting static quark-antiquark potential. This provides a
             basis for the construction of (classically) perfect lattice
             actions for QCD using staggered fermions. © 1997 Elsevier
             Science B.V.},
   Key = {fds245727}
}

@article{fds245728,
   Author = {Chandrasekharan, S},
   Title = {A large N chiral transition on a plaquette},
   Journal = {Physics Letters, Section B: Nuclear, Elementary Particle and
             High-Energy Physics},
   Volume = {395},
   Number = {1-2},
   Pages = {83-88},
   Year = {1997},
   Abstract = {We construct a model of a chiral transition using the well
             known large N transition in two dimensional U(N) lattice
             gauge theory. Restricting the model to a single plaquette,
             we introduce Grassmann variables on the corners of the
             plaquette with the natural phase factors of staggered
             fermions and couple them to the U(N) link variables. The
             classical theory has a continuous chiral symmetry which is
             broken at strong couplings, but is restored for weak
             couplings in the N → ∞ limit. * This work is supported
             in part by funds provided by the U.S. Department of Energy
             (D.O.E.) under cooperative research agreement
             #DF-FC02-94ER40818.},
   Key = {fds245728}
}

@article{fds245729,
   Author = {Chandrasekharan, S and Wiese, U-J},
   Title = {Quantum link models: A discrete approach to gauge
             theories},
   Journal = {Nuclear Physics B},
   Volume = {492},
   Number = {1-2},
   Pages = {455-471},
   Year = {1997},
   Abstract = {We construct lattice gauge theories in which the elements of
             the link matrices are represented by non-commuting operators
             acting in a Hubert space. These quantum link models are
             related to ordinary lattice gauge theories in the same way
             as quantum spin models are related to ordinary classical
             spin systems. Here U (1) and SU (2) quantum link models are
             constructed explicitly. As Hamiltonian theories quantum link
             models are non-relativistic gauge theories with potential
             applications in condensed matter physics. When formulated
             with a fifth Euclidean dimension, universality arguments
             suggest that dimensional reduction to four dimensions
             occurs. Hence, quantum link models are also reformulations
             of ordinary quantum field theories and are applicable to
             particle physics, for example to QCD. The configuration
             space of quantum link models is discrete and hence their
             numerical treatment should be simpler than that of ordinary
             lattice gauge theories with a continuous configuration
             space. © 1997 Published by Elsevier Science
             B.V.},
   Key = {fds245729}
}

@article{fds245730,
   Author = {Bietenholz, W and Brower, R and Chandrasekharan, S and Wiese,
             U-J},
   Title = {Progress on perfect lattice actions for QCD},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {53},
   Number = {1-3},
   Pages = {921-934},
   Year = {1997},
   Abstract = {We describe a number of aspects in our attempt to construct
             an approximately perfect lattice action for QCD. Free quarks
             are made optimally local on the whole renormalized
             trajectory and their couplings are then truncated by
             imposing 3-periodicity. The spectra of these short ranged
             fermions are excellent approximations to continuum spectra.
             The same is true for free gluons. We evaluate the
             corresponding perfect quark-gluon vertex function,
             identifying in particular the "perfect clover term". First
             simulations for heavy quarks show that the mass is strongly
             renormalized, but again the renormalized theory agrees very
             well with continuum physics. Furthermore we describe the
             multigrid formulation for the non-perturbative perfect
             action and we present the concept of an exactly (quantum)
             perfect topological charge on the lattice.},
   Key = {fds245730}
}

@article{fds245731,
   Author = {Chandrasekharan, S and Huang, S},
   Title = {Z3 twisted chiral condensates in QCD at finite
             temperatures.},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {53},
   Number = {9},
   Pages = {5100-5104},
   Year = {1996},
   Month = {May},
   ISSN = {0556-2821},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/10020507},
   Abstract = {It was recently observed in a lattice QCD measurement that
             the chiral condensate in the quenched approximation shows
             dramatically different behavior in the three Z3-equivalent
             deconfined phases. We argue that this phenomenon can be
             understood qualitatively as an effect of Z3 twists on
             fermionic fields. Quarks under these Z3 twists become global
             anyons and, hence, display different thermodynamic
             properties. We further show that the lattice data can be
             roughly modeled by a Nambu-Jona-Lasinio-type Lagrangian with
             a minimal coupling to a constant gauge field A0=2Ï€nT/3
             (with n=0,±1), which arises naturally from the nontrivial
             phase of the Polyakov line.},
   Key = {fds245731}
}

@article{Chandrasekharan:1995gt,
   Author = {Chandrasekharan, Shailesh and Christ, Norman
             H.},
   Title = {Dirac Spectrum, Axial Anomaly and the QCD Chiral Phase
             Transition},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {47},
   Pages = {527-534},
   Year = {1996},
   url = {http://arxiv.org/pdf/hep-lat/9509095},
   Abstract = {http://arxiv.org/abs/hep-lat/9509095},
   Key = {Chandrasekharan:1995gt}
}

@article{fds245732,
   Author = {Chandrasekharan, S and Christ, N},
   Title = {Dirac spectrum, axial anomaly and the QCD chiral phase
             transition},
   Journal = {Nuclear Physics B - Proceedings Supplements},
   Volume = {47},
   Number = {1-3},
   Pages = {527-534},
   Year = {1996},
   url = {http://dx.doi.org/10.1016/0920-5632(96)00115-6},
   Abstract = {The QCD phase transition is studied on 163 and 323 × 4
             lattices both with and without quark loops. We introduce a
             new zero-flavor or quenched species of quark ζ and study
             the resulting chiral condensate, ζ̄ζ as a function of the
             ζ mass, mζ. By examining ζ̄ζ for 10-10 ≤ mζ ≤ 10
             we gain considerable information about the spectrum of Dirac
             eigenvalues. A comparison of ma = 0.01 and 0.025 shows
             little dependence of the Dirac spectrum on such a light,
             dynamical quark mass, after an overall shift in β is
             removed. The presence of sufficient small eigenvalues to
             support anomalous chiral symmetry breaking in the high
             temperature phase is examined quantitatively. In an effort
             to enhance these small eigenvalues, ζ̄ζ is also examined
             in the pure gauge theory in the region of the deconfinement
             transition with unexpected results. Above the critical
             temperature, the three Z3 phases show dramatically different
             chiral behavior. Surprisingly, the real phase shows chiral
             symmetry, suggesting that a system with one flavor of
             staggered fermion at Nt = 4 will possess a chiral a phase
             transition - behavior not expected in the continuum
             limit.},
   Doi = {10.1016/0920-5632(96)00115-6},
   Key = {fds245732}
}

@article{Chandrasekharan:1995nf,
   Author = {Chandrasekharan, S and Huang, S},
   Title = {Z3 twisted chiral condensates in QCD at finite
             temperatures},
   Journal = {Physical Review D - Particles, Fields, Gravitation and
             Cosmology},
   Volume = {53},
   Number = {9},
   Pages = {5100-5104},
   Year = {1996},
   url = {http://arxiv.org/pdf/hep-ph/9512323},
   Abstract = {It was recently observed in a lattice QCD measurement that
             the chiral condensate in the quenched approximation shows
             dramatically different behavior in the three Z3-equivalent
             deconfined phases. We argue that this phenomenon can be
             understood qualitatively as an effect of Z3 twists on
             fermionic fields. Quarks under these Z3 twists become global
             anyons and, hence, display different thermodynamic
             properties. We further show that the lattice data can be
             roughly modeled by a Nambu-Jona-Lasinio-type Lagrangian with
             a minimal coupling to a constant gauge field A0=2πnT/3
             (with n=0,±1), which arises naturally from the nontrivial
             phase of the Polyakov line.},
   Key = {Chandrasekharan:1995nf}
}

@article{Chandrasekharan:1994cq,
   Author = {Chandrasekharan, Shailesh},
   Title = {Critical behavior of the chiral condensate at the QCD phase
             transition},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {42},
   Pages = {475-477},
   Year = {1995},
   url = {http://arxiv.org/pdf/hep-lat/9412070},
   Abstract = {http://arxiv.org/abs/hep-lat/9412070},
   Key = {Chandrasekharan:1994cq}
}

@article{fds245734,
   Author = {Chandrasekharan, S},
   Title = {Critical behavior of the chiral condensate at the QCD phase
             transition},
   Journal = {Nuclear Physics, Section B: Proceedings Supplements},
   Volume = {42},
   Number = {1-3},
   Pages = {475-477},
   Year = {1995},
   ISSN = {0920-5632},
   url = {http://dx.doi.org/10.1016/0920-5632(95)00284-G},
   Abstract = {We study the critical behavior of the chiral condensate near
             the QCD phase transition in the background of two fixed
             light dynamical (sea) quarks. We study the condensate for
             5.245 ≤ β ≤ 5.3 and 10-10 ≤ mval ≤ 10 (in lattice
             units) on a 163 × 4 lattice using staggered fermions with
             msea fixed at 0.01. © 1995 Elsevier Science B.V. All rights
             reserved.},
   Doi = {10.1016/0920-5632(95)00284-G},
   Key = {fds245734}
}

@article{fds245735,
   Author = {Chandrasekharan, S},
   Title = {Anomaly cancellation in 2+1 dimensions in the presence of a
             domain wall mass.},
   Journal = {Physical Review D: Particles, Fields, Gravitation and
             Cosmology},
   Volume = {49},
   Number = {4},
   Pages = {1980-1987},
   Year = {1994},
   Month = {February},
   ISSN = {0556-2821},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/10017182},
   Abstract = {A fermion in 2+1 dimensions, with a mass function which
             depends on one spatial coordinate and passes through a zero
             (a domain wall mass), in the background of an Abelian gauge
             field is considered. In this model, originally proposed in a
             non-Abelian version by Callan and Harvey, the gauge
             variation of the effective gauge action mainly consists of
             two terms. One comes from the induced Chern-Simons term and
             the other from the chiral fermions, bound to the
             (1+1)-dimensional wall, and they are expected to cancel each
             other. Though there exist arguments in favor of this, based
             on the possible forms of the effective action valid far from
             the wall and some facts about theories of chiral fermions in
             1+1 dimensions, a complete calculation is lacking. In this
             paper we present an explicit calculation of this
             cancellation at one loop which is valid even close to the
             wall. We show that integrating out the ``massive'' modes of
             the theory does produce the Chern-Simons term, as
             appreciated previously. In addition, we show that it
             generates a term that softens the high energy behavior of
             the (1+1)-dimensional effective chiral theory thereby
             resolving an ambiguity present in a general
             (1+1)-dimensional theory.},
   Key = {fds245735}
}

@article{Chandrasekharan:1993ag,
   Author = {Chandrasekharan, Shailesh},
   Title = {Anomaly cancellation in (2+1)-dimensions in the presence of
             a domain wall mass},
   Journal = {Phys. Rev. D},
   Volume = {49},
   Pages = {1980-1987},
   Year = {1994},
   url = {http://arxiv.org/pdf/hep-th/9311050},
   Abstract = {http://arxiv.org/abs/hep-th/9311050},
   Key = {Chandrasekharan:1993ag}
}

@article{Chandrasekharan:1994ae,
   Author = {Chandrasekharan, S.},
   Title = {Fermions with a domain wall mass: Explicit Greens function
             and anomaly cancellation},
   Journal = {Nucl. Phys. Proc. Suppl.},
   Volume = {34},
   Pages = {579-582},
   Year = {1994},
   Key = {Chandrasekharan:1994ae}
}

@article{Chandrasekharan:1994kx,
   Author = {Chandrasekharan, S.},
   Title = {CRITICAL BEHAVIOR AT THE QCD PHASE TRANSITION WITH TWO
             MASSLESS QUARK FLAVORS},
   Booktitle = {Continuous Advances in QCD},
   Publisher = {World Scientific},
   Editor = {Smilga, A.V.},
   Year = {1994},
   Key = {Chandrasekharan:1994kx}
}

@book{fds4165,
   Author = {S. Chandrasekharan},
   Title = {CRITICAL BEHAVIOR AT THE QCD PHASE TRANSITION WITH TWO
             MASSLESS QUARK FLAVORS},
   Booktitle = {Continuous Advances in QCD},
   Publisher = {World Scientific},
   Editor = {Andrei V. Smilga},
   Year = {1994},
   Key = {fds4165}
}

@article{fds245733,
   Author = {Chandrasekharan, S},
   Title = {Fermions with a domain-wall mass: explicit greens function
             and anomaly cancellation},
   Journal = {Nuclear Physics, Section B: Proceedings Supplements},
   Volume = {34},
   Number = {C},
   Pages = {579-582},
   Year = {1994},
   ISSN = {0920-5632},
   Abstract = {We calculate the explicit Greens function for fermions in
             2+1 dimensions, with a domain wall mass. We then show a
             calculation demonstrating the anomaly cancellation when such
             fermions move in the background of an abelian gauge field.
             © 1994.},
   Key = {fds245733}
}