Path Integrals and Applications

Eugene P. Gross

RAMAMURTI RAJARAMAN

Dinkar C. Khandekar, S. V. Lawande, K.V. Bhagwat

Concepts of Lagrangian and Hamiltonian path integrals Wiener integrals and Brownian motion representation of the statistical mechanical density matrix as a path integral propagators for local and non-local quadratic actions path integrals in polar and curvilinear coordinates and group manifolds local and global time transformation techniques approximation and numerical methods of evaluating path integrals and their applications to polaron bi polaron spectrum of disordered systems path integrals with topological constraints and their applications

R. MacKenzie

These lectures are intended as an introduction to the technique of path integrals and their applications in physics. The audience is mainly first-year graduate students, and it is assumed that the reader has a good foundation in quantum mechanics. No prior exposure to path integrals is assumed, however. The path integral is a formulation of quantum mechanics equivalent to the standard formulations, offering a new way of looking at the subject which is, arguably, more intuitive than the usual approaches. Applications of path integrals are as vast as those of quantum mechanics itself, including the quantum mechanics of a single particle, statistical mechanics, condensed matter physics and quantum field theory. After an introduction including a very brief historical overview of the subject, we derive a path integral expression for the propagator in quantum mechanics, including the free particle and harmonic oscillator as examples. We then discuss a variety of applications, including path integrals in multiply-connected spaces, Euclidean path integrals and statistical mechanics, perturbation theory in quantum mechanics and in quantum field theory, and instantons via path integrals. For the most part, the emphasis is on explicit calculations in the familiar setting of quantum mechanics, with some discussion (often brief and schematic) of how these ideas can be applied to more complicated situations such as field theory.

Масуд Чайчиан, A Demichev

In order to give the reader an idea about the different approaches to the construction of path integrals and their main applications, we present schematically the general pattern in figure 2.5 (page 319). Obviously, it is impossible to reflect in a single figure the many different path-integral applications and thus this diagram may serve only for a preliminary orientation in the subject and for visualizing the links which exist among various topics discussed in this monograph.