Field-dependent symmetries in Friedmann-Robertson-Walker models

TL;DR

This paper explores the fermionic BRST invariance of FRW cosmological models, demonstrating how finite field-dependent BRST transformations can relate different gauges and modify the effective action.

Contribution

It introduces finite field-dependent BRST transformations in FRW models and explicitly computes their Jacobian, showing their role in gauge transformations.

Findings

Finite field-dependent BRST transformations relate different gauges in FRW models.

Explicit Jacobian calculation shows additional terms in the effective action.

Transformations preserve the generating functional under specific parameter choices.

Abstract

We consider effective actions of the cosmological Friedmann-Robertson-Walker (FRW) models and discuss their fermionic rigid BRST invariance. Further, we demonstrate the finite field-dependent BRST transformations as a limiting case of continuous field-dependent BRST transformations described in terms of continuous parameter $\kappa$. The Jacobian under such finite field-dependent BRST transformations is computed explicitly, which amounts an extra piece in the effective action within functional integral. We show that for a particular choice of the parameter the finite field-dependent BRST transformation maps the generating functional for FRW models from one gauge to another.