This book is a systematic study of the classical and quantum theories of
gauge systems. It starts with Dirac's analysis showing that gauge
theories are constrained Hamiltonian systems. The classical foundations
of BRST theory are then laid out with a review of the necessary concepts
from homological algebra. Reducible gauge systems are discussed, and the
relationship between BRST cohomology and gauge invariance is carefully
explained. The authors then proceed to the canonical quantization of
gauge systems, first without ghosts (reduced phase space quantization,
Dirac method) and second in the BRST context (quantum BRST cohomology).
The path integral is discussed next. The analysis covers indefinite
metric systems, operator insertions, and Ward identities. The antifield
formalism is also studied and its equivalence with canonical methods is
derived. The examples of electromagnetism and abelian 2-form gauge
fields are treated in detail.
The book gives a general and unified treatment of the subject in a
self-contained manner. Exercises are provided at the end of each
chapter, and pedagogical examples are covered in the text.