SYMMETRICAL SPIRALS IN MEDIA WITH RELAXATION KINETICS AND 2 DIFFUSINGSPECIES

We find an approximate solution for the shape and rotation frequency o f spirals in excitable media with anti-symmetric kinetics and diffusio n in both species. Using singular perturbation theory, we approximate the governing diffusion-reaction system with a free boundary problem a nd then map this free boundary problem onto a fixed domain problem. Th e resulting fixed domain problem is viewed as a nonlinear eigenvalue p roblem which can be solved iteratively using a numerical shooting algo rithm. Solutions of the approximate free boundary problem are compared with numerical solutions of the full system of diffusion reaction equ ations and shown to be in good agreement.