Mathematical Methods of Many-Body Quantum Field Theory offers a comprehensive, mathematically rigorous treatment of many-body physics. It develops the mathematical tools for describing quantum many-body systems and applies them to the many-electron system. These tools include the formalism of second quantization, field theoretical perturbation theory, functional integral methods, bosonic and fermionic, and estimation and summation techniques for Feynman diagrams. Among the physical effects discussed in this context are BCS superconductivity, s-wave and higher l-wave, and the fractional quantum Hall effect. While the presentation is mathematically rigorous, the author does not focus solely on precise definitions and proofs, but also shows how to actually perform the computations.
Presenting many recent advances and clarifying difficult concepts, this book provides the background, results, and detail needed to further explore the issue of when the standard approximation schemes in this field actually work and when they break down. At the same time, its clear explanations and methodical, step-by-step calculations shed welcome light on the established physics literature.INTRODUCTION SECOND QUANTIZATION Coordinate and Momentum Space The Many-Electron System Annihilation and Creation Operators PERTURBATION THEORY The Perturbation Series for e(H0+lV) The Perturbation Series for the Partition Function The Perturbation Series for the Correlation Functions GAUSSIAN INTEGRATION AND GRASSMANN INTEGRALS Why Grassmann Integration? A Motivating Example Grassmann Integral Representations Ordinary Gaussian Integrals Theory of Grassmann Integration BOSONIC FUNCTIONAL INTEGRAL REPRESENTATION The Hubbard Stratonovich Transformation The Effective Potential BCS THEORY AND SPONTANEOUS SYMMETRY BREAKING The Quadratic Mean Field Model The Quartic BCS Model