Abstract:
Abstract. Experiments on a quasi-two-dimensional
Belousov--Zhabotinsky (BZ) reaction-diffusion system,
periodically forced at approximately twice its natural
frequency, exhibit resonant labyrinthine patterns that
develop through two distinct mechanisms. In both cases,
large amplitude labyrinthine patterns form that consist of
interpenetrating fingers of frequency-locked regions
differing in phase by $\pi$. Analysis of a forced complex
Ginzburg--Landau equation captures both mechanisms observed
for the formation of the labyrinths in the BZ experiments: a
transverse instability of front structures and a nucleation
of stripes from unlocked oscillations. The labyrinths are
found in the experiments and in the model at a similar
location in the forcing amplitude and frequency parameter plane.