..., and derives the BBGKY hierarchy of equations for their evolution. This yields a new way to analyze the evolution of mass clustering in an expanding universe. Of course, the main interest in the approach comes from the thought that the observed galaxy correlation functions may yield useful approximations...

... and an n-particle phase space probability density function is constructed to derive the Liouville equation. This is deconstructed into the BBGKY hierarchy, and radial distribution functions are used to develop n-body correlation functions. Koopman–von Neumann theory...

..., are defined and it is shown that the average values of usual properties can be computed in term of these. The dynamical equations for the reduced distributions---the BBGKY hierarchy---are obtained. These are not closed, putting in evidence the need for approximations appropriate to different conditions...

...This chapter introduces to the study of the dynamics of many-body systems. The reduced distribution functions and their dynamics, determined by the equations of the BBGKY hierarchy, are presented. It is explained how kinetic theories are based on plausible approximations of the first equations...