Supernatural A-term Inflation

TL;DR

This paper investigates A-term inflation within supersymmetric models with low SUSY breaking scales, demonstrating that certain flat directions can serve as inflatons under specific potential conditions, broadening the viable parameter space.

Contribution

It extends previous work by analyzing low-scale SUSY breaking scenarios, showing that MSSM flat directions can successfully drive inflation with a suitable potential structure.

Findings

Inflation is feasible for a wide range of potential values $V_0$ with TeV-scale soft masses.

Flat directions with superpotential terms $p=4,5,6$ can act as inflatons under specific $V_0$ conditions.

The model supports inflation with non-renormalizable terms and a false vacuum component.

Abstract

Following \cite{Lin:2009yt}, we explore the parameter space of the case when the supersymmetry (SUSY) breaking scale is lower, for example, in gauge mediated SUSY breaking model. During inflation, the form of the potential is $V_0$ plus MSSM (MSSM stands for Minimal Supersymmetric Standard Model) (or A term (It is called A-term inflation when the inflaton field is any direction (gauge or singlet) that generates an A-term.)) inflation. We show that the model works for a wide range of the potential $V_0$ with the soft SUSY breaking mass $m\sim O(1)$ TeV. The implication to MSSM (or A-term) inflation is that the flat directions which is lifted by the non-renormalizable terms described by the superpotential $W=\lambda_p \phi^{p-1}/M^{p-3}_P$ with $p=4$ and $p=5$ are also suitable to be an inflaton field for $\lambda_p=O(1)$ provided there is an additional false vacuum term $V_0$ with appropriate magnitude. The flat directions corresponds to $p=6$ also works for $0 \lae V_0/M_P^4 \lae 10^{-40}$.