Thermally activated escape far from equilibrium: A unified path-integral approach

Thermally activated escape over potential barriers is addressed for systems driven out of equilibrium by time-dependent forces, temperatures, or dissipation coefficients of rather general type. Particular examples are periodic perturbations, single pulses, and the initial convergence towards Kramers rate in a time-independent set up. The general problem is treated within one common, unifying path-integral approach in the simplest case of an overdamped, one-dimensional model dynamics. As an application, the following quite astonishing effect is demonstrated: for a suitably chosen, but still quite simple static potential landscape, the net escape rate may be substantially reduced by temporally increasing the temperature above its unperturbed, constant level.