REFERENCE SYSTEM APPROACH IN THE ELECTRON LIQUID THEORY .1. GENERAL RELATIONS

A new formalism of the statistical description of the electron liquid is proposed. The renormalized statistical perturbation theory is formulated in terms of n-particle correlation functions of some simpler model system, called the reference system. The functional representations of the partition function. free energy, ground state energy, and two-particle correlation function are obtained for quantum systems on the basis of the method of collective variables. The approach under consideration describes, in particular, the strongly coupled electron liquid, it is general enough and can be generalized to the case of superconducting electron systems, systems in external fields, and also Bose systems.