Dispersion gap and localized spiral waves in a model for intracellular Ca2+ dynamics

The dispersion relation is the dependence of the velocity of periodic plana r wave trains on their wavelength. We study the occurrence of a velocity ga p in the dispersion relation in a bistable three component reaction-diffusi on system modeling intracellular Ca2+ dynamics. In two spatial dimensions, localized pinned spirals are observed, if their wavelength falls into the d ispersion gap. Destruction of free spirals occurs already for conditions wh ere the asymptotic planar wave train exists and the dispersion gap is absen t.