SEMINAIRE MERCREDI 25 FEVRIER 2004
14 heures
Salle Séminaire 5
Centre de Physique Théorique
Marseille-Luminy

Michael Rosenblum
Nonlinear Dynamics Group, University of Potsdam

Title: Controlling synchronization in complex systems

Summary: Synchronization phenomena are abundant in physical, chemical and
biological systems. After an introduction to the synchronization
theory, with an emphasis on recent achievements in understanding the
phase synchronization of chaotic oscillators, I will consider two
problems of synchronization control.
First, I will demonstrate that the coherence of a noisy or chaotic
self-sustained oscillator can be efficiently controlled by the delayed
feedback and will discuss applications of the effect for the control
of locking.
Next, I will present a technique to control coherent collective
oscillations in ensembles of globally coupled units (self-sustained
oscillators or maps, periodic or chaotic). I will present numerical
and theoretical results demonstrating that a time delayed feedback in
the mean field can, depending on the parameters, enhance or suppress
the self-synchronization in the population. In particular, the
populations of neurons will be considered. I will discuss possible
applications of the technique in neuroscience, as an approach to
quench pathological brain rhythms.