Regensburg 2013 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 12: Nonlinear Dynamics, Synchronization and Chaos I

DY 12.4: Vortrag

Dienstag, 12. März 2013, 10:15–10:30, H48

Noise-induced oscillations in network motifs of non-linear oscillators with delay — •Andrea Vüllings¹, Valentin Flunkert^2,1, and Eckehard Schöll¹ — ¹Technische Universität Berlin, Germany — ²IFISC, Palma de Mallorca, Spain

We investigate noise-induced oscillations of network motifs composed of non-linear oscillators (super- or subcritical Hopf-normal forms), which are paradigmatic for neural networks and coupled semiconductor lasers. Fluctuations are modeled by Gaussian white noise, and finite signal propagation velocities are accounted for by a time-delayed coupling. Using a self-consistent mean-field approach, we study stochastic synchronization and compare our results with numerical simulations. We find that the delay can enhance or destroy the collective oscillations in a network motif depending upon the delay time. For the supercritical case with nonzero amplitude-phase coupling (corresponds to the linewidth enhancement factor in semiconductor-laser physics) a noise-induced frequency shift of the oscillations is observed. In the case of noisy subcritical Hopf-normal forms we observe coherence resonance. We study numerically the effect of the time delay on the optimal noise strength in the coupled system.