Nonperturbative calculation of symmetry breaking in quantum field theory

TL;DR

This paper introduces a novel delta expansion method enabling nonperturbative calculations of symmetry breaking in self-interacting scalar quantum field theories, demonstrated through first-order expectation value computations.

Contribution

A new delta expansion technique is developed for nonperturbative analysis of symmetry breaking in scalar quantum field theories.

Findings

Successfully computes expectation values to first order in delta.

Enables analysis of symmetry breaking beyond perturbation theory.

Provides a framework for future nonperturbative studies.

Abstract

A new version of the delta expansion is presented, which, unlike the conventional delta expansion, can be used to do nonperturbative calculations in a self-interacting scalar quantum field theory having broken symmetry. We calculate the expectation value of the scalar field to first order in delta, where delta is a measure of the degree of nonlinearity in the interaction term.