Non-Markovian activated rate processes: Comparison of current theories with numerical simulation data

We calculate the barrier crossing rate constants for a Brownian particle in a double well potential experiencing a non-Markovian friction kernel using a full stochastic simulation. We compare the simulation results with recently proposed interpolation formulas which are based on the Grote–Hynes theory and the energy diffusion mechanism. We find that such formulas can fail by orders of magnitude in a physically interesting regime. Slow activation in an effective dynamic double well potential is probably responsible for the deviations observed.