On the intermediate time behavior of the stress tensor and velocity autocorrelation functions for dense hard sphere systems

Abstract

It is conjectured that the large values at intermediate times of the stress tensor autocorrelation function, found in computer simulations, may be caused by a coupling of the stress tensor to pairs of slowly decaying extended heat modes of large wave number. Approximate expressions, amenable to numerical verification, are given for both the stress tensor and the velocity autocorrelation function.