Coarse graining of slow variables in dynamic simulations of soft matter

Computational Biophysics, Faculty of Science and Technology, University of Twente P.O. Box 217, 7500 AE Enschede, The Netherlands

Corresponding author: w.j.briels@utwente.nl

Received: 23 March 2007
Accepted: 21 August 2007

Abstract

A new Brownian dynamics model is presented to describe the coarse grain dynamics of particles with long-lived memory. Instead of solving a set of generalized Langevin equations we introduce a set of variables describing the slowly fluctuating thermodynamic state of the ignored degrees of freedom. These variables give rise to additional transient forces on the simulated particles, whose interpretation provides a new way of thinking about memory effects in soft-matter physics. We illustrate the proposed method by simulating shear thinning of synthetic resins.