ABSTRACT
The principal goal of this textbook is the development of the foundations of the Lagrangian theory of Galilean and relativistic fields and particles at an introductory undergraduate level using primarily, as examples, classical electromagnetism and the gravitational interaction. No attem pt will be made to give a standard or complete treatment of electrodynamics even at the non-quantum level, and a complete general relativistic treatment of gravity in curved spacetime will not be included. Instead, we shall con centrate on those relativistic and Lagrangian features of electromagnetism which illustrate the principles of internal and spacetime symmetries and fa cilitate a comparison with the other three interactions. To highlight these relativistic features we shall compare the properties of electrodynamics with those of the gravitational interaction treated both non-relativistically and with special relativity in flat spacetime.
