Excitable front geometry in reaction-diffusion systems with anomalous dispersion.

Abstract

Two-dimensional excitable systems with anomalous dispersion provide a discrete set of interpulse distances for the stable propagation of planar wave trains. Numerical simulations show that the trailing front of a pulse pair can undergo transitions between these stable distances. In response to localized perturbations, the trailing front converges towards one of numerous, sigmoidal shapes. Their transition segments move at constant speeds and can collide and fuse with each other. A complementing kinematic analysis of the front dynamics yields a reaction-diffusion-like equation.