Investigation of Bogolyubov's chain of equations for strongly correlated statistical systems

General aspects of motion of a perfect gas are investigated on the basis of Bogolyubov's chain of equations for the $s$-point distribution functions. It is shown that the kinetics of an inhomogeneous perfect gas satisfies a special chain of equations which reduces to the classical Boltzmann equation only in the particular case when there are no statistical constraints in the macrospace. The investigation of this chain of equations enables one to approach rigorously the question of the hydrodynamic equations for a continuous medium when there are statistical constraints at different spatial points in the medium. In particular, it is shown that the equilibrium state of a perfect gas differs strongly from the usual Maxwell state if such constraints are present.