Production of spin 3/2 particles from vacuum fluctuations

TL;DR

This paper investigates the generation of spin 3/2 particles, such as gravitinos, from vacuum fluctuations in cosmological backgrounds, using mode-mixing techniques within a supergravity inflationary context.

Contribution

It introduces a simplified method to analyze spin 3/2 particle production by reducing the problem to a Dirac fermion calculation, applied to supergravity inflation models.

Findings

Calculated the spectrum of gravitinos produced during preheating.

Demonstrated the applicability of standard fermion techniques to spin 3/2 particles.

Provided insights into vacuum fluctuation effects in early universe cosmology.

Abstract

We study the production of spin 3/2 particles in homogeneous scalar and gravitational backgrounds from the mode-mixing Bogolyubov method. Considering only helicity $\pm 3/2$ states we can reduce the problem to a standard Dirac fermion calculation and apply the standard techniques in a straightforward way. As an example we consider a supergravity inflationary model and calculate the spectrum of gravitinos created during preheating at the end of inflation.