Intermittent generalized synchronization in unidirection - ally coupled chaotic oscillators

– A new behavior type of unidirectionally coupled chaotic oscillators near the generalized synchronization transition has been detected. It has been shown that the generalized synchronization appearance is preceded by the intermitted behavior: close to threshold parameter value the coupled chaotic systems demonstrate the generalized synchronization most of the time, but there are time intervals during which the synchronized oscillations are interrupted by non-synchronous bursts. This type of the system behavior has been called intermitted generalized synchronization (IGS) by analogy with intermitted lag synchronization (ILS) [Phys. Rev. Synchronization [1,2] of interacting chaotic oscillators is one of the fundamental phenomena of nonlinear dynamics. Recently several types of chaotic synchronization have been observed in coupled nonlinear oscillators. These are phase synchronization (PS) [3–5], lag synchronization (LS) [6–8], complete synchronization (CS) [9–12] and generalized synchronization (GS) [13– 15]. It is important to note that GS may also takes place in the non-oscillatory chaotic systems (see [16] for detail). All synchronization types are interrelated (see for detail [7, 13, 17]), but the relationship between them is not completely clarified yet. In recent works [18–21] it has been shown that all these synchronization types may be considered from the common point of view as different manifestations of one universal phenomenon. It has also been found that onsets of phase and lag synchronization types are preceded by intermittent behavior. Close to the threshold parameter value the coupled chaotic systems demonstrate synchronized dynamics most of the time, but there are time intervals during which the synchronized oscillations are interrupted by non-synchronous behavior. These pre– transitional intermittencies have been described in [6,22,23] for the case of lag synchronization and in [24–26] for phase synchronization, respectively. Due to the existence of unifying framework of coupled chaotic oscillators synchronization one can also expect the intermitted behavior at the threshold of the generalized synchronization appearance. In this work we consider the behavior of coupled chaotic oscillators close to the coupling parameter value corresponding to the onset of generalized synchronization regime. As it will be shown below the generalized synchronization appearance is also preceded by the intermitted behavior in the same way as the phase synchronization and lag c EDP Sciences