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

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.