Construction of theory of a binary mixture of nonideal bose gases (or liquids) by the method of collective variables. II. The $s$-particle density matrices at $T=0$. Variational calculation of the ground-state energy and density-density correlation functions

In the framework of collective variables method for binary mixture of non-ideal Bose-gases (liquids) $s$-particle density matrices at $T=0$ are found. The ground state energy, the excitation spectrum and correlation functions “density-density” are calculated by means of variational method. The accordance between zero-order approximations of the variational and microscopic approaches is demenstrated. Binary mixture of Bose-gases of equal masses is taken as an example of a model of the “pseudopotential of hard spheres”.