Drawn from the 24th International Workshop on Condensed Matter Theories (Buenes Aires, Sep. 2000) these 45 papers, while centered on the concepts and techniques of condensed-matter physics, also address broad issues of common concern for theorists who apply advanced many-particle methods in other areas of physics. Five primary topics are covered by the contributions: quantum liquids, boson condensates, strongly-correlated electron systems, superconductivity and superfluidity, and phase transitions. Some of examples of specific questions addressed include shot noise of mesoscopic quantum systems, heat transport in superlattices, transitions from non-colinear to conlinear structures in a magnetic multilayer model, order-disorder transitions in a vortex lattice, perturbation theory in the one-phase region of an electron-ion system, and nonlinear dynamics in metal clusters. Annotation c. Book News, Inc., Portland, OR (booknews.com)