Langevin approach to the dynamics of interacting Brownian particles

Abstract

Describes an approach to the dynamics of particles in liquid suspension, based on Langevin equations, which allows rather direct calculation of power series expansions in time tau of such quantities as the particle velocity autocorrelation function, mean-square displacement and dynamic structure factors. The expansions are evaluated to order tau ³ if hydrodynamic interactions are neglected, but only to order tau in their presence. The longer-time diffusion coefficients are also considered, and the importance of the structural relaxation time tau _I to the theoretical development is emphasised. Further similarities between the dynamics of particle suspensions and atoms in simple fluids are pointed out.