Master Functional And Proper Formalism For Quantum Gauge Field Theory

Understand

We develop a general field-covariant approach to quantum gauge theories.

• Extending the usual set of integrated fields and external sources to "proper" fields and sources, which include partners of the composite fields, we define the master functional Omega, which collects one-particle irreducible diagrams and upgrades the usual Gamma-functional in several respects.
• The functional Omega is determined from its classical limit applying the usual diagrammatic rules to the proper fields.
• Moreover, it behaves as a scalar under the most general perturbative field redefinitions, which can be expressed as linear transformations of the proper fields.