Techniques and Applications of Path Integration

Part I Introduction 1 Introduction and Defining the Path Integral Appendix: The Trotter Product Formula 2 Probabilities and Probability Amplitudes for Paths 3 Correspondence Limit for the Path Integral (Heuristic) Appendix: Useful Integrals 4 Vector Potentials and Another Proof of the Path Integral Formula 5 The Ito Integral and Gauge Transformations 6 Doing the Integral: Free Particle and Quadratic Lagrangians Appendix: Exactness of the Sum over Classical Paths 7 Properties of Green's Functions; the Feynman-Kac Formula 8 Functional Derivatives and Commutation Relations 9 Brownian Motion and the Wiener Integral; Kac's Proof 10 Perturbation Theory and Feynman Diagrams Part II Selected Applications of the Path Integral 11 Asymptotic Analysis 12 The Calculus of Variations 13 The WKB Approximation and its Application to the Anharmonic Oscillator 14 Detailed Presentation of the WKB Approximation 15 WKB Near Caustics 16 Caustics and Uniform Asymptotic Approximations 17 The Phase of the Semiclassical Amplitude 18 The Semiclassical Propagator as a Function of Energy 19 Scattering Theory 20 Geometrical Optics 21 The Polaron 22 Spin and Related Matters 22.1 The Direct Method-Product Integrals or Time Ordered Products 22.2 Continuous Models for Spin 23 Path Integrals for Multiply Connected Spaces 23.1 Particle Constrained to a Circle 23.2 Rudiments of Homotopy Theory 23.3 Homotopy Applied to the Path Integral 23.4 Extensions of Symmetric Operators 24 Quantum Mechanics on Curved Spaces 25 Relativistic Propagators and Black Holes 26 Applications to Statistical Mechanics 27 Coherent State Representation 28 Systems with Random Impurities 29 Critical Droplets, Alias Instantons, and Metastability Appendix: Small Oscillations about the Instanton 30 Renormalization and Scaling for Critical Phenomena 31 Phase Space Path Integral 32 Omissions, Miscellany, and Prejudices 32.1 Field Theory 32.2 Uncompleting the Square 32.3 Rubber: Path Integral Formulation of a Polymer as a Random Walk 32.4 Hard Sphere Gas Second Virial Coefficient 32.5 Adding Paths by Computer 32.6 A Perturbation Expansion Using the Path Integral 32.7 Solvable Path Integral with the Potential ax2 + b/x2 32.8 Superfluidity 32.9 Fermions 32.10 Books and Review Papers on Path Integrals Author Index Subject Index Supplements