Michael Rudolf Vogl

This textbook provides a self-contained introduction to many-body theory that bridges the gap between the standard graduate curriculum and more research-oriented courses in many-body theory. The author systematically constructs the basic formalism of many-body theory, starting from Newton's second law, and subsequently develops action principles and symmetry-based techniques. Upon switching to quantum theory, second quantization and the Feynman path integral are introduced. After a treatment of statistical mechanics from an information-entropy perspective, which allows for a simple understanding of temperature dependent variational principles, the book switches to a coherent state path-integral formulation. This approach makes diagrammatic perturbation theory, linear response techniques, and renormalization group methods, which are treated in later parts of the book, accessible to a broad audience. The content of the book is based on a set of lectures on the Quantum Theory of Solids that the author has taught at King Fahd University of Petroleum and Minerals (KFUPM) every year since 2022. With detailed, explicit computations and...