ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book establishes the connections between response and correlation functions and the extent to which these may be related to the spectrum of elementary excitations. Because of the long range of the Coulomb interaction, a charged Fermi liquid differs appreciably from its neutral counterpart. The book describes the new physical features introduced by the Coulomb interaction, screening and plasma oscillation. The Landau theory is generalized and applied to the description of a number of macroscopic phenomena encountered in electron liquids. The book deals with certain exact relationships between various physical quantities, or with macroscopic theories, whose validity is limited to phenomena in the macroscopic regime. It presents the treatments in parallel as much as possible, in order to emphasize the similarities in behavior of the two kinds of superfluids.
