Functional Integrals and Collective Excitations [Paperback]

This book describes the theory and selected applications of one of the most important mathematical tools used in the theoretical investigation of collective excitations in statistical physics, such as occur in superfluidity, superconductivity, plasma dynamics, superradiation, and in phase transitions.A distinguished physicist and leading researcher describes the theory and selected applications of one of the most important mathematical tools used in the theoretical investigation of collective excitations in statistical physics.A distinguished physicist and leading researcher describes the theory and selected applications of one of the most important mathematical tools used in the theoretical investigation of collective excitations in statistical physics.Written by a distinguished physicist and leading researcher, this volume describes the theory and selected applications of one of the most important mathematical tools used in the theoreticial investigation of collective excitations in statistical physics. The text offers an introduction to functional integral techniques in equilibrium statistical physics, and discusses the expression of partition functions and Green functions in terms of functional integrals. Sections of the book deal with the application of functional integrals in superfluid Bose systems, systems with Coulomb interaction, and superfluid Fermi systems. The book also considers the application of the concept of Bose-condensation of auxiliary fields to the theory of crystals, heavy atoms and also to the theory of model Hamiltonians.Part I. Functional Integrals and Diagram Techniques in Statistical Physics: Part II. Superfluid Bose Systems: Part III. Plasma and Superfluid Fermi Systems: Part IV. Crystals, Heavy Atoms, Model Hamiltonians. ...exposition is clear, mathematical details appearing for the first time are worked out in detail, and, what is particularly important, the physical implications of various results are discussed...solid physical argumel³1