EVENT DETAILS AND ABSTRACT

Title: Noise-induced dynamics in bistable systems with delay
Speaker: Lev Tsimring, Institute for Nonlinear Science, University of California
Speaker Info: San Diego
Brief Description:
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Abstract:

In non-equilibrium systems, noise is known to produce surprising effects such as noise-induced phase transitions, stochastic resonance, etc. In this talk, we will consider noise-induced dynamics of a prototypical bistable system with delayed feedback. For small noise and magnitude of the feedback, the problem can be reduced to analysis of the two-state model with certain transition rates which depend on the earlier state of the system. In this two-state approximation, we find analytical formulae for the autocorrelation function, the power spectrum, and the linear response to a periodic perturbation. They show very good agreement with direct numerical simulations of the original Langevin equation. The power spectrum has a pronounced peak at the frequency corresponding to the inverse delay time, whose amplitude has a maximum at a certain noise level, thus demonstrating coherence resonance. The linear response to the external periodic force also has maxima at the frequencies corresponding to the inverse delay time and its harmonics.