Synchronization regimes in coupled noisy excitable systems - art. no. 026201

We study synchronization regimes in a system of two coupled noisy excitable systems which exhibit excitability close to an Andronov bifurcation. The u ncoupled system possesses three fixed points: a node, a saddle, and an unst able focus. We demonstrate that with an increase of coupling strength the s ystem undergoes transitions from a desynchronous state to a train synchroni zation regime to a phase synchronization regime, and then to a complete syn chronization regime. Train synchronization is a consequence of the existenc e of a saddle in the phase space. The mechanism of transitions in coupled n oisy excitable systems is different from that in coupled phase-coherent cha otic systems.