Book excerpt: Our understanding of the physical world was revolutionized in the twentieth century — the era of 'modern physics'. Three texts presenting the foundations and frontiers of modern physics have been published by the second author. Many problems are included in these books. The current authors have published solutions manuals for two of the texts Introduction to Modern Physics: Theoretical Foundations and Topics in Modern Physics: Theoretical Foundations.The present book provides solutions to the over 180 problems in the remaining text Advanced Modern Physics: Theoretical Foundations. This is the most challenging material, ranging over advanced quantum mechanics, angular momentum, scattering theory, lagrangian field theory, symmetries, Feynman rules, quantum electrodynamics (QED), higher-order processes, path-integrals, and canonical transformations for quantum systems; several appendices supply important details.This solutions manual completes the modern physics series, whose goal is to provide a path through the principal areas of theoretical physics of the twentieth century in sufficient detail so that students can obtain an understanding and an elementary working knowledge of the field. While obtaining familiarity with what has gone before would seem to be a daunting task, these volumes should help the dedicated student to find that job less challenging, and even enjoyable.