Many-body partition function and thermal Hartree-Fock approximations

Abstract

The derivation of hierarchy equations for the quantum thermal density matrices of an assembly of interacting particles in an external potential is discussed. The method replaces the phenomenological treatment of the thermodynamic properties of quantum gasses, liquids, and solids. A temperature Hartree-Fock approximation for fermions based on the symmetry properties of the exact hierarchy was also derived. The approximation was discussed in relation to that of Kaplan and Argyres.