Inflaton Decay in Supergravity and Gravitino Problem

TL;DR

This paper investigates how inflaton decay in supergravity models leads to gravitino overproduction, deriving constraints to prevent cosmological issues related to excess gravitinos.

Contribution

It provides a detailed analysis of inflaton decay channels in supergravity and establishes new constraints on inflation and supersymmetry breaking models to avoid gravitino overproduction.

Findings

Inflaton couples to matter fields and gauge sectors via supergravity anomalies.

Inflaton decay produces a significant number of gravitinos.

Derived constraints limit inflation and SUSY breaking models to prevent gravitino overproduction.

Abstract

We have recently shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the supergravity. Through these processes, the inflaton decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. Taking account of these processes, we derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos.