Inflaton Decay in Supergravity

TL;DR

This paper analyzes how the inflaton decays in supergravity, highlighting its couplings to matter and gauge sectors, and discusses constraints to prevent excessive gravitino production while enabling decay into the visible sector.

Contribution

It provides a detailed analysis of inflaton decay channels in supergravity, including gravitational effects and implications for gravitino overproduction.

Findings

Inflaton couples to matter fields and gauge sectors through supergravity effects.

Decays into the supersymmetry breaking sector produce gravitinos.

Constraints are derived to avoid gravitino overproduction.

Abstract

We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is 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 generically decays into the supersymmetry breaking sector, producing many gravitinos. The inflaton also directly decays into a pair of the gravitinos. We derive constraints on both inflation models and supersymmetry breaking scenarios for avoiding overproduction of the gravitinos. Furthermore, the inflaton naturally decays into the visible sector via the top Yukawa coupling and SU(3)_C gauge interactions.