  The pilot wave interpretation proposed by de Broglie and later by Bohm
contains not only a dynamical ontology but also relies on a statistical
assumption known as quantum equilibrium. In this work which follows our recent
article [1] we develop a Langevin force description of the relaxation process
which leads to quantum equilibrium. Based on a application of the
Caldera-Leggett model for a thermal bath we show how a Brownian motion leads
naturally to quantum relaxation.
