Effect of parameter mismatch on the mechanism of chaos synchronization loss in coupled systems

Using the example of two coupled logistic maps, we investigate the effect of nonidentical subsystems on the bifurcations of saddle periodic orbits embedded in a symmetric chaotic attractor. These bifurcations determine the process of loss of chaos synchronization. We show that if bifurcations conditioned by the symmetry of the system take part in the synchronization loss process, nonidentity changes the bifurcation scenario of the transition to a nonsynchronous regime. In this case, for example, the transition to the bubbling behavior is determined not by bifurcation of an orbit embedded in the chaotic attractor but by the smooth shift of it and the saddle-repeller bifurcation of the birth of new orbits in the vicinity of the quasisymmetric region. [S1063-651X(98)10909-1].