Activated escape of periodically modulated systems

Abstract

The rate of noise-induced escape from a metastable state of a periodically modulated overdamped system is found for an arbitrary modulation amplitude $A$. The instantaneous escape rate displays peaks that vary with the modulation from Gaussian to strongly asymmetric. The prefactor $\nu$ in the period-averaged escape rate depends on $A$ nonmonotonically. Near the bifurcation amplitude $A_c$ it scales as $\nu \propto (A_c-A{)}^{\zeta }$. We identify three scaling regimes, with $\zeta =1/4,-1$, and 1/2.