Phase front dynamics in inhomogeneously forced oscillatory systems

Resonantly forced reaction-diffusion systems possess phase-locked domains separated by phase fronts. A nonequilibrium. Ising-Bloch bifurcation in which a stationary Ising front loses stability to a pair of counterpropagating Bloch fronts with opposite chirality exists in 2:1 forced systems. For such systems, we study the effects of a spatially inhomogeneous forcing intensity which varies in space across the bifurcation. In such a case, a propagating Bloch front which encounters a domain where the forcing intensity lies in the Ising regime undergoes a change in chirality and is reflected from the Ising domain. This phenomenon is studied analytically and numerically in one dimension. In two dimensions systems with regular and disordered forcing are studied; the spatial arrangement of Ising domains may give rise to complex pattern dynamics. (C) 2002 Elsevier Science B.V. All fights reserved.