The Quantum Action Principle in the framework of Causal Perturbation Theory

TL;DR

This paper formulates and proves the Quantum Action Principle within causal perturbation theory, using the Master Ward Identity to maintain classical symmetries in quantum field theory.

Contribution

It introduces a new framework for the Quantum Action Principle in causal perturbation theory with localized interactions, unifying symmetry preservation methods.

Findings

Proves the Quantum Action Principle in the causal perturbation theory framework.

Establishes the Master Ward Identity as a universal symmetry formulation.

Enhances understanding of symmetry maintenance in quantum field theory.

Abstract

In perturbative quantum field theory the maintenance of classical symmetries is quite often investigated by means of algebraic renormalization, which is based on the Quantum Action Principle. We formulate and prove this principle in a new framework, in causal perturbation theory with localized interactions. Throughout this work a universal formulation of symmetries is used: the Master Ward Identity.