# Gravitino Problem in Minimal Supergravity Inflation

## TL;DR

This paper investigates the production of gravitinos in minimal supergravity inflation models, revealing potential issues with energy transfer during reheating that could challenge the theory's validity or cause cosmological problems.

## Contribution

It introduces a minimal supergravity inflation model with orthogonal nilpotent superfields and analyzes non-thermal gravitino production and its implications.

## Key findings

- Significant energy transfer to longitudinal gravitino during reheating
- Potential breakdown of effective theory during reheating
- Serious gravitino problem identified in the model

## Abstract

We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find that a substantial fraction of the cosmic energy density can be transferred to the longitudinal gravitino due to non-trivial change of its sound speed. This implies either a breakdown of the effective theory during reheating or a serious gravitino problem.