Classical dynamics of a coupled double well oscillator in condensed media. II

Abstract

The influence exerted on reaction processes by the coupling between the reaction coordinate x and transverse nonreactive modes is discussed. Attention is mainly focused on the synergism of inertia and multiplicative fluctuation, which enhances the reaction rate throughout a wide domain, ranging from the high to the low-friction region. The high-friction region is explored by applying the adiabatic elimination procedure (AEP) described in the first paper of this series: When the relaxation time of x is larger than that of the nonreactive mode, a new term occurs. This term is shown to be responsible for making the ‘‘noise-induced phase transition effects’’ discussed in the first paper more pronounced. The low-friction region is explored with a first-passage time procedure by using energy as the slow variable. The synergism of inertia and multiplicative noise is then shown to produce finite reaction rates even in conditions where Kramers theory predicts them to be vanishingly small.