DRIFT OF SPIRAL WAVES IN EXCITABLE MEDIA

The motion of a spiral wave in excitable media due to interaction with various kinds of boundaries is considered both in the case of small d iffusion of the slow field and for the diffusionless case, The drift o f the core and the frequency shift of the spiral due to distant bounda ries or inhomogeneities in the media are found to be a superexponentia lly weak function of the distance from the core. It is shown that for some range of parameters the spiral drifts away from the center of a c ircular domain. It is also shown that the spiral can form a bound stat e with a plane boundary as well as with a small topological defect. Nu merical simulations are performed demonstrating qualitative agreement with the analytical results.