addresses the phenomenon of superfluidity/superconductivity through an emergent, topologically protected constant of motion and covers topics developed over the past 20 years. The approach is based on the idea of separating universal classical-field superfluid properties of matter from the underlying system’s “quanta.” The text begins by deriving the general physical principles behind superfluidity/superconductivity within the classical-field framework and provides a deep understanding of all key aspects in terms of the dynamics and statistics of a classical-field system. It proceeds by explaining how this framework emerges in realistic quantum systems, with examples that include liquid helium, high-temperature superconductors, ultra-cold atomic bosons and fermions, and nuclear matter. The book also offers several powerful modern approaches to the subject, such as functional and path integrals. Comprised of 15 chapters, this text: