Quantum field theory forms the present theoretical framework of physics of elementary particles and their interactions. This up-dated and expanded text examines gauge theories and their symmetries with an emphasis on their physical and technical aspects.
Beginning with a new chapter giving a systematic introduction to classical field theories and a short discussion of their canonical quantization and the discrete symmetries C, P and T, the book provides a brief exposition of perturbation theory, the renormalization programme, and the use of the renormalization group equation. It then explores topics of current research interest including chiral symmetry and its breaking, anomalies, and low energy effective lagrangians and some basics of supersymmetry. A chapter on the basics of the electroweak theory is now included.