Critical Viscosity and Diffusion in the Binary-Liquid Phase Transition

Abstract

The fluctuation-dissipation formula for the viscosity in terms of the stress-tensor fluctuations reproduces the experimental logarithmic temperature dependence of the hydrodynamic viscosity. Using the theoretical wave-number- and frequency-dependent viscosity in the problem of critical diffusion, we find that the effects of nonlocality and retardation practically cancel, resulting in satisfactory agreement with a recent light-scattering determination of the effective viscosity.