Publications [#345586] of Kirsten G. Wickelgren

Papers Published

1. Wickelgren, K, On 3-nilpotent obstructions to π1 sections for ℙ1ℚ-{0,1,∞}, in Arithmetic of Fundamental Groups Pia 2010 (January, 2012), pp. 281-328, ISBN 9783642239045 [doi]
   (last updated on 2026/01/24)

   Abstract:
   We study which rational points of the Jacobian of ℙ¹-{0,1,∞} can be lifted to sections of geometrically 3-nilpotent quotients of étale π1 over the absolute Galois group. This is equivalent to evaluating certain triple Massey products of elements of k* ⊆ H¹(Gk, ℤ(1)) or H¹(Gk,ℤ/2ℤ). For k = ℚp or R, we give a complete mod 2 calculation. This permits some mod 2 calculations for k = ℚ. These are computations of obstructions of Jordan Ellenberg.