Hydrodynamic Theory of the Angular Velocity Autocorrelation Function

The angular velocity correlation function is computed using a frequency dependent version of Stokes' Law. The drag torque on a sphere rotating nonuniformly about one of its diagonals is used to compute the relaxation of the angular velocity. It is shown that the asymptotic time dependence of this function goes as t−5/2. Consequences of this persistence in the orientational relaxation of molecules is discussed.