Amazon.com description: Product Description: The goal of this textbook is to understand the forces of nature in their simplest and most general terms. It begins in Part 1 with a detailed discussion of transformation theory, which is used by the author to formulate advanced quantum theory in group-theoretical language. Part 2 deals with scattering theory and includes many applications to nuclear, atomic, and solid-state physics. The central theme of the book, however, is presented in Part 3: relativistic Feynman diagrams. The student learns to use them in a most natural way and will find a thorough discussion of the lowest-order electromagnetic, strong, weak, and gravitational interactions. The last chapter deals with the finite parts of higher-order graphs in field theory and dispersion theory. In the second edition errors have been eliminated and the text has been enhanced with the inclusion of new sections on the quark model.