This book is a very early systematic treatment of the application of the field-theoretical methods developed after the Second World War to the quantum mechanical many-body problem at finite temperature. It describes various techniques that remain basic tools of modern condensed matter physicists.

>and G< -- The Hartree and Hartree-Fock Approximations -- Effect of Collisions on G -- A Technique for Deriving Green's Function Approximations -- Transport Phenomena -- The Hartree Approximation, the Collisionless Boltzmann Equation, and the Random Phase Approximation -- Relation between Real and Imaginary Time Response Functions -- Slowly Varying Disturbances and the Boltzmann Equation -- Quasi-Equilibrium Behavior: Sound Propagation -- The Landau Theory of the Normal Fermi Liquid -- The Shielded Potential -- The T Approximation -- Appendix: Finite-Temperature Perturbation Theory