Slow dynamics of self-diffusion in metastable colloidal fluids

A simple theory for nonequilibrium density fluctuations in concentrated hard-sphere suspensions of interacting Brownian particles with both hydrodynamic and direct interactions is proposed. The correlation effects due to the many-body hydrodynamic interactions among particles are shown to cause a structural arrest in the relaxation of nonequilibrium density fluctuations. A volume fraction dependence of slow relaxation process in concentrated colloidal suspensions is thus explored from a new unifying point of view.