The equivalence theorem and the production of gravitinos after inflation

TL;DR

This paper investigates the high-energy equivalence between helicity 1/2 gravitinos and goldstinos to accurately compute gravitino production in dynamic backgrounds, introducing a Landau gauge for simplification.

Contribution

It extends the equivalence theorem to time-dependent backgrounds, addressing subtleties from external sources, and proposes the Landau gauge as a practical tool.

Findings

Derived the equivalence for equations of motion with external sources

Proposed the Landau gauge as a simplification method

Provided a framework for gravitino production calculations

Abstract

We study the high-energy equivalence between helicity 1/2 gravitinos and goldstinos in order to calculate the production of gravitinos in time-dependent scalar and gravitational backgrounds. We derive this equivalence for equations of motion, paying attention to some subtleties, mainly due to external sources, that are not present in the standard proofs. We also propose the Landau gauge as a simplifying alternative to the usual gauge choices, both for practical calculations and in the equivalence theorem proof.