Variational Approach to Quantum Field Theory: Gaussian Approximation and the Perturbative Expansion around It
Abstract
Description
The functional Schrodinger picture formulation of quantum field theory and the variational Gaussian approximation method based on the formulation are briefly reviewed. After presenting recent attempts to improve the variational approximation, we introduce a new systematic method based on the background field method, which enables one to compute the order-by-order correction terms to the Gaussian approximation of the effective action.
To appear in the proceedings of APCTP-ICTP Joint International Conference '97 on "Recent Developments in Nonperturbative Quantum Field Theory". new references are added
To appear in the proceedings of APCTP-ICTP Joint International Conference '97 on "Recent Developments in Nonperturbative Quantum Field Theory". new references are added