The Schwinger Action Principle and Effective Action

by David J. Toms

Overview

This book is an introduction to the Schwinger action principle in quantum mechanics and quantum field theory, with applications to a variety of different models including Bose-Einstein condensation, the Casimir effect, and trapped Fermi gases. The book begins with a brief review of the action principle in classical mechanics and classical field theory. It then moves on to quantum field theory, focusing on the effective action method. This is introduced as simply as possible by using the zero-point energy of the simple harmonic oscillator as the starting point. The book concludes with a more complete definition of the effective action, and demonstrates how the provisional definition used earlier is the first term in the systematic loop expansion. The renormalization of interacting scalar field theory is presented to two-loop order. This book will interest graduate students and researchers in theoretical physics who are familiar with quantum mechanics.

Product Details

ISBN-13:	9780521876766
Publisher:	Cambridge University Press
Publication date:	11/15/2007
Series:	Cambridge Monographs on Mathematical Physics
Edition description:	New Edition
Pages:	508
Product dimensions:	7.00(w) x 9.80(h) x 1.20(d)

About the Author

David Toms is Reader in Mathematical Physics in the School of Mathematics and Statistics at Newcastle University. Prior to joining Newcastle University, Dr Toms was a NATO Science Fellow at Imperial College London, and a postdoctoral fellow at the University of Wisconsin-Milwaukee. His research interests include the formalism of quantum field theory and its applications, and his most recent interests are centred around Kaluza-Klein theory, based on the idea that there are extra spatial dimensions beyond the three obvious ones.

Table of Contents

Preface; 1. Action principle in classical mechanics; 2. Action principle in classical field theory; 3. Action principle in quantum theory; 4. The effective action; 5. Quantum statistical mechanics; 6. Effective action at finite temperature; 7. Further applications of the Schwinger action principle; 8. General definition of the effective action; Appendices; References; Index.