Introduction

In the preceding parts we analyzed the thermodynamic properties of systems in the canonical ensemble. In this part we will get acquainted with a generalization of the canonical ensemble to systems that can exchange particles with their surroundings. This generalization, the grand canonical ensemble, which we present in Chap. 1, is of double importance. On the one hand it contributes to a deeper understanding of the statistical physics of classical particles. On the other hand, the new ensemble is the natural tool for the development of statistical mechanics of systems of identical particles in quantum conditions. This is not because a system of (nonrelativistic) quantum-mechanical particles does not conserve the number of particles. It is merely of great technical convenience and is analogous to the application of the canonical ensemble to isolated systems, which have a constant energy…