This book provides a detailed exposition of field theoretical methods as applied to zero temperature Fermi liquids. It is a product of a course taught in 1959–1960 at the University of Paris in the "Troisieme Cycle" of Theoretical and Solid-State Physics.

This book provides a comprehensive overview of some key developments in the understanding of the nucleon-nucleon interaction and nuclear many-body theory. The main problems at the level of meson exchange physics have been solved, and we have an effective field theory using a phenomenological interaction pioneered by Achim Schwenk and Scott Bogner, which is nearly universally accepted as a unique low-momentum interaction that includes all experimental data to date.This understanding is based on a multi-step development in which different scientific insights and a wide range of physical and mathematical methodologies fed into each other. It is best appreciated by looking at the different 'steps along the way', starting with the pioneering work of Brueckner and his collaborators that was just as necessary and important as the insightful masterly improvements to Brueckner's theory by Hans Bethe and his students. Moving on from there, the off-shell effects that bedeviled Bethe's work — which had resulted in the 1963 Reference Spectrum Method — were treated relatively accurately by introducing an energy gap between initial bound states and an intermediate state. With their influential 1967 paper, Brown and Kuo prepared the effective field theory. Later, the introduction of 'Brown-Rho scaling' deepened understanding of saturation in the many-body system and fed directly into recent work on carbon-14 dating.

This book provides a comprehensive overview of some key developments in the understanding of the nucleon-nucleon interaction and nuclear many-body theory. The main problems at the level of meson exchange physics have largely been solved, and we now have an effective nucleon-nucleon interaction, pioneered in a renormalization group formalism by several of us at Stony Brook and our colleagues at Naples, which is nearly universally accepted as the unique low-momentum interaction that includes all experimental information to date.Our present understanding of these issues is based on a multi-step development in which different scientific insights and a wide range of physical and mathematical methodologies fed into each other. It is best appreciated by looking at the ‘steps along the way’, starting with the pioneering work of Brueckner and his collaborators that was just as necessary and important as the insightful improvements to Brueckner's theory by Hans Bethe and his students. Moving on from there, microscopic methods for nuclear structure calculations using the Brueckner G-matrix, and later low-momentum nucleon interactions, were developed and applied. With their influential 1967 paper, Brown and Kuo prepared the effective theory that allowed the description of nuclear properties directly from the underlying nucleon-nucleon interaction. Later, the addition of ‘Brown-Rho scaling’ to the one-boson-exchange model deepened the understanding of nuclear matter saturation, carbon-14 dating and the structure of neutron stars.