“…Apart from a fundamental scientific interest in developing and extending systematic methods of kinetic theory, our studies are motivated by the following physical reasons: Firstly, a wide variety of complex systems, such as colloidal suspensions, polymers, micelles etc., can be viewed as interacting Brownian particles that are in contact with a heat bath [7,8,9]. There are several approaches to the statistical description of Brownian dynamics where interaction between particles is taken into account, see, e.g., [10,11,12,13,14], and references therein. In the case of a Gaussian external field, the system investigated in our paper can be considered as a "prototype" of that of interacting Brownian particles.…”