Role of multistability in the transition to chaotic phase synchronization

In this paper we describe the transition to phase synchronization for syste ms of coupled nonlinear oscillators that individually follow the Feigenbaum route to chaos. A nested structure of phase synchronized regions of differ ent attractor families is observed. With this structure, the transition to nonsynchronous behavior is determined by the loss of stability for the most stable synchronous mode. It is shown that the appearance of hyperchaos and the transition from lag synchronization to phase synchronization are relat ed to the merging of chaotic attractors from different families. Numerical examples using Rossler systems and model maps are given. (C) 1999 American Institute of Physics. [S1054-1500(99)00201-3].