The Early Universe with High-Scale Supersymmetry

TL;DR

This paper explores how high-scale supersymmetry influences early universe cosmology, showing that hybrid inflation models with small tensor-to-scalar ratio are consistent with data and can evade gravitino overproduction.

Contribution

It demonstrates a model-independent framework linking high-scale supersymmetry with inflation, including a new inflaton linear term and implications for reheating and gravitino production.

Findings

Hybrid inflation with small r fits experimental data.

Reheating temperature can be below leptogenesis threshold with perturbative decay.

Gravitino overproduction is avoided due to kinematic blocking.

Abstract

A small tensor-to-scalar ratio $r$ may lead to distinctive phenomenology of high-scale supersymmetry. Assuming the same origin of SUSY breaking between the inflation and visible sector, we show model independent features. The simplest hybrid inflation, together with a new linear term for the inflaton field which is induced by large gravitino mass, is shown to be consistent with all experimental data for $r$ of order $10^{-5}$. For superpartner masses far above the weak scale we find that the reheating temperature after inflation might be beneath the value required by thermal leptogenesis if the inflaton decays to its products perturbatively, but above it if non-perturbatively instead. Remarkably, the gravitino overproduction can be evaded in such high-scale supersymmetry because of the kinematically blocking effect.