Average lifetimes of a metastable state at low barrier in the overdamped regime

Thermal decay of a metastable state is a process revealing itself in particular in the contemporary single-molecule pulling experiments. Unfortunately, some approaches used for the interpretations of these experiments in the literature are incorrect and misleading. We prove this statement in the present work. For this aim, the most important characteristic of the decay process which is the average lifetime of a Brownian particle in a metastable state is considered. For this state two typical potentials are used: the Lennard-Jones and cubic potentials. We concentrate on the case of strong friction (overdamped regime) and low barrier since these conditions are typical for the mentioned experiments. We calculate the average lifetimes using five approaches, including dynamical modeling, and compare them with each other.