Path Integrals In Quantum Mechanics, Statistics, Polymer Physics, And Financial Markets (4th Edition)

This is the fourth, expanded edition of the comprehensive textbook published in 1990 on the theory and applications of path integrals. It is the first book to explicitly solve path integrals of a wide variety of nontrivial quantum-mechanical systems, in particular the hydrogen atom. The solutions have become possible by two major advances. The first is a new euclidean path integral formula which increases the restricted range of applicability of Feynman's famous formula to include singular attractive 1/r and 1/r2 potentials. The second is a simple quantum equivalence principle governing the transformation of euclidean path integrals to spaces with curvature and torsion, which leads to time-sliced path integrals that are manifestly invariant under coordinate transformations.In addition to the time-sliced definition, the author gives a perturbative definition of path integrals which makes them invariant under coordinate transformations. A consistent implementation of this property leads to an extension of the theory of generalized functions by defining uniquely integrals over products of distributions.The powerful Feynman-Kleinert variational approach is explained and developed systematically into a variational perturbation theory which, in contrast to ordinary perturbation theory, produces convergent expansions. The convergence is uniform from weak to strong couplings, opening a way to precise approximate evaluations of analytically unsolvable path integrals.Tunneling processes are treated in detail. The results are used to determine the lifetime of supercurrents, the stability of metastable thermodynamic phases, and the large-order behavior of perturbation expansions. A new variational treatment extends the range of validity of previous tunneling theories from large to small barriers. A corresponding extension of large-order perturbation theory also applies now to small orders.Special attention is devoted to path integrals with topological restrictions. These are relevant to the understanding of the statistical properties of elementary particles and the entanglement phenomena in polymer physics and biophysics. The Chern-Simons theory of particles with fractional statistics (anyons) is introduced and applied to explain the fractional quantum Hall effect.The relevance of path integrals to financial markets is discussed, and improvements of the famous Black-Scholes formula for option prices are given which account for the fact that large market fluctuations occur much more frequently than in the commonly used Gaussian distributions.The author's other book on ‘Critical Properties of φ4 Theories’ gives a thorough introduction to the field of critical phenomena and develops new powerful resummation techniques for the extraction of physical results from the divergent perturbation expansions.

Table of Contents:
Fundamentals; Path Integrals -- Elementary Properties and Simple Solutions; External Sources, Correlations, and Perturbation Theory; Semiclassical Time Evolution Amplitude; Variational Perturbation Theory; Path Integrals with Topological Constraints; Many Particle Orbits -- Statistics and Second Quantization; Path Integrals in Polar and Spherical Coordinates; Wave Functions; Spaces with Curvature and Torsion; Schrodinger Equation in General Metric-Affine Spaces; New Path Integral Formula for Singular Potentials; Path Integral of Coulomb System; Solution of Further Path Integrals by Duru-Kleinert Method; Path Integrals in Polymer Physics; Polymers and Particle Orbits in Multiply Connected Spaces; Tunneling; Nonequilibrium Quantum Statistics; Relativistic Particle Orbits; Path Integrals and Financial Markets.

Review :
"Kleinert's book presents the reader with a very complete and very thorough discussion of path integration ... a new extensive and, again, rather complete chapter has been added on the use of path integration techniques in the analysis of financial markets. This chapter would do well in any high-level course on stochastic financial models and is a wonderful occasion for candidate mathematical and theoretical physicists to realize what great potential there hides still in the methodologies and techniques that have been developed ... It profits from the clarity and conciseness that is also a hallmark of Kleinert's scientific papers ... this volume is highly recommendable for any student considering majoring in theoretical physics or chemistry, and an absolute must for any lecturer in this area ... In fact, I don't know of any excuse not to have your own copy."Journal of Statistical Physics"Nobody possibly is better suited to write a book about path integrals than Hagen Kleinert. He contributed extensively to the method. Feynman, who pioneered the technique, stopped teaching the path integral approach to quantum mechanics when he realized that he could not solve, by this technique, such a fundamental problem as the hydrogen atom. He suggested the problem to Kleinert who finally did solve it ... In addition to covering these subjects in great detail, the technique is applied to polymer physics (effect of topological restrictions such as in entanglement problems), tunneling and non-equilibrium processes. This is an advanced textbook, rigorous, thorough and complete."Physics in Canada"The book of Hagen Kleinert became very popular and serves as an encyclopedia on path integral (PI) methods ... it is of help for students as well as for qualified physicists and mathematicians."Zentralblatt MATH"If you get a copy of Kleinert's book you will know that you have the best single book on the subject: the depth of knowledge and exposition is representative of a true master scholar ... this book is not only a genuine classic, it is a true bargain."Australian Physics