Traveling-wave fragments in anisotropic excitable media

Abstract

Experiments with an anisotropic chemical excitable medium---a catalytic chemical reaction on a single crystal surface---reveal a kind of stable wave pattern representing single traveling-wave fragments. Their existence is attributed to the presence of a strong state-dependent diffusion anisotropy in the medium. A simple theory of traveling fragments setting general conditions for their observation is proposed. Its conclusions are confirmed by numerical simulations of a reaction-diffusion model. Our analysis suggests that traveling-wave fragments are a general property of excitable media with strong state-dependent anisotropy.