LONG-TIME BEHAVIOR OF THE ANGULAR VELOCITY AUTOCORRELATION FUNCTION

In this Communication we present a hydrodynamic analysis to show that the asymptotic long-time tail of the angular velocity autocorrelation function of a Brownian particle is independent of the particle's size or shape-a result in agreement with simulation and in accord with prev ious predictions from microscopic theories. The reason that earlier hy drodynamic treatments had predicted a shape dependent tail is because they implicitly assumed the particle to have a fixed orientation. Reor ientation of the particle must be included to obtain the true long-tim e behavior. (C) 1996 American Institute of Physics.