Influence of the critical curvature on spiral initiation in an excitable medium

Abstract
Spiral waves are created in a Belousov-Zhabotinsky medium due to the presence of some inert obstacle placed into that medium. The eikonal equation, which is completely valid when the excitability of the system remains constant, is shown to be insufficient when media with different excitabilities are used, as predicted by Zykov’s kinematical theory [Biophys. 25, 906 (1980)], where two parameters, excitability and curvature, are varied.