LONG-TIME BATH CORRELATIONS IN THE POLLAK-GRABERT-HANGGI THEORY

We analyze some cases for which the Pollak-Grabert-Hanggi theory on th e activated rate processes for generalized Langevin dynamics exhibits unexplained disagreements with numerical results. First we analyze car efully the PGH theory and we show that a kind of Markovian hypothesis implicitly made in the reasoning is sometimes violated. Then we propos e modifications of the original theory in order to take into account t he possible effects caused by this violation, and we compare the corre cted results with simulations.