The St\"uckelberg formalism is a field-enlarging transformation

TL;DR

The paper demonstrates that the St"uckelberg formalism acts as a field-enlarging transformation adding gauge symmetry, with a new approach linking it to BRST charge and physical state conditions, and compares it to the BFV method.

Contribution

It introduces a novel perspective on the St"uckelberg formalism as a field-enlarging transformation with an associated BRST charge, connecting it to physical state conditions.

Findings

The St"uckelberg formalism can be viewed as a field-enlarging transformation.

A BRST charge corresponding to the formalism can be constructed.

The approach is applied to various models and compared with the BFV procedure.

Abstract

It is shown that the St\"uckelberg formalism can be regarded as a field-enlarging transformation that introduces an additional gauge symmetry to the considered model. The appropriate BRST charge can be defined. The physical state condition, demanding that that a physical state is to be anihilated by the BRST charge, is shown to be equivalent to the St\"uckelberg condition. Several applications of the new approach to the formalism are presented. The comparison with the BFV procedure is given. (The author field has been corrected.)