Reduced description method in the kinetic theory of Brownian motion with active fluctuations

Abstract

We develop a microscopic approach to the kinetic theory of many-particle systems with dissipative and potential interactions in the presence of active fluctuations. The approach is based on a generalization of the Bogolyubov–Peletminskii reduced description method applied to the systems of many active particles. It is shown that the microscopic approach developed allows us to construct the kinetic theory of two- and three-dimensional systems of active particles in the presence of nonlinear friction (dissipative interaction) and an external random field with active fluctuations. The kinetic equations for these systems in the case of a weak interaction between the particles (both potential and dissipative ones) and low-intensity active fluctuations are obtained. We demonstrate particular cases in which the derived kinetic equations have solutions that match the results known in the literature. In addition, analysis of particular solutions showed that in the case of a friction force linearly dependent on the speed of structural units, the manifestation of self-propelling properties in the process of evolution of an active medium may be due to the local nature of active fluctuations.