Abstract:
In the framework of the theory of the canonical ensemble, a rigorous mathematical
description is given of equilibrium states of quantum systems that satisfy Bose or
Fermi statistics at low densities. Study of the properties of the solutions of the
corresponding Kirkwood–Salsburg equations leads to proof of the existence and
uniqueness of limit partial density matrices of the canonical ensemble as analytic
functions of the density; the equivalence of the canonical and the grand canonical
ensembles in the thermodynamic limit is proved.