Gauge Invariances in Second Class Constrained Systems - A Comparative Look at Two Methods

TL;DR

This paper compares two methods for inducing gauge invariances in second class constrained systems, revealing that the additional field in one method can be derived from the original phase space.

Contribution

It provides a comparative analysis of the Batalin-Fradkin and Gauge Unfixing methods, highlighting their similarities and differences in gauge invariance induction.

Findings

The extra field in the Batalin-Fradkin method can be obtained from the original phase space.

Both methods are applicable to various systems with second class constraints.

The comparison clarifies the relationship between the two approaches.

Abstract

We look at and compare two different methods developed earlier for inducing gauge invariances in systems with second class constraints. These two methods, the Batalin-Fradkin method and the Gauge Unfixing method, are applied to a number of systems. We find that the extra field introduced in the Batalin-Fradkin method can actually be found in the original phase space itself.