Reheating in an early supersymmetric universe

TL;DR

This paper develops a supergravity-based model of inflation and preheating in the MSSM framework, highlighting the crucial impact of flat direction VEVs and supergravity effects on particle production after inflation.

Contribution

It introduces a consistent supergravity model incorporating flat directions with large VEVs, emphasizing the significance of supergravity and non-renormalizable terms in preheating dynamics.

Findings

Flat directions acquire large VEVs during inflation without disrupting slow-roll.

Supergravity effects significantly influence particle production during preheating.

Efficient preheating from the inflaton is possible despite large flat direction VEVs.

Abstract

Motivated by a recent discussion about the role of flat directions, a typical feature of supersymmetric models, in the process of particle production in the early universe a consistent model of inflation and preheating in supergravity with MSSM fields has been built. It is based on a model proposed by M. Kawasaki, M. Yamaguchi and T. Yanagida. In the inflationary stage, the flat directions acquire large vacuum expectation values (VEVs) without spoiling the background of slow-roll, high-scale inflation consistent with the latest WMAP5 observational data. In the stage of particle production, naturally following inflation, the role of flat direction large VEVs depends strongly on effects connected with the supergravity framework and non-renormalizable terms in the superpotential, which have been neglected so far in the literature. Such effects turn out to be very important, changing the previous picture of preheating in the presence of large flat direction VEVs by allowing for efficient preheating from the inflaton.