Nonlocal hydrodynamic equations and BBGKY hierarchy reduction for hard spheres

We discuss the derivation of the kinetic equation for a classical system of hard spheres based on an infinite sequence of equations for distribution functions in the BBGKY hierarchy case. It is well known that the assumption of full synchronization of all distributions leads to certain problems in describing the “tails” of the autocorrelation functions and some other correlation effects with medium or high density. We show how to avoid these difficulties by maintaining the explicit form of time-dependent dynamic correlations in the BBGKY closure scheme.