Spiral wave motion in reaction-diffusion systems

We consider spiral waves in reaction-diffusion systems. One example is the light sensitive Belousov-Zhabotinsky reaction. Due to the Euclidean SE(2)-symmetry, in the spatially homogeneous case spiral wave patterns appear, which rotate rigidly around the fixed tip position of the spiral. We are interested in the persistence of such solutions under a symmetry breaking perturbation, which still keeps a discrete lattice symmetry. In particular we study the resulting tip motions via a reduction of the original PDE-systems to vectorfields on the two-dimensional torus. Our methods include global center manifold reductions.