WAVE INSTABILITIES IN EXCITABLE MEDIA WITH FAST INHIBITOR DIFFUSION

An excitable activator-inhibitor system with relatively fast inhibitor diffusion is considered. Numerical simulations of wave propagation in side long channels show transitions from stable flat traveling waves t o folded waves and further to spreading spiral turbulence as the inhib itor diffusivity is increased. For sufficiently narrow channels the su ppression of turbulence and the development of regular steadily propag ating patterns is observed. The curvature dependence of the wave propa gation velocity is derived and used to interpret the observed phenomen a.