Inflation and Dark Energy with a Single Superfield

TL;DR

This paper examines the challenges of constructing supergravity models with a single superfield that can account for inflation and the tiny cosmological constant, highlighting the limitations imposed by a no-go theorem and the implications for supersymmetry breaking.

Contribution

It demonstrates that small modifications cannot uplift Minkowski vacua to de Sitter vacua without breaking supersymmetry significantly, providing insights into model building constraints.

Findings

Small parameter modifications lead to AdS vacua and rapid collapse.

Large modifications can uplift to dS vacua but cause strong supersymmetry breaking.

The no-go theorem constrains simple superfield inflation models.

Abstract

We discuss the possibility to construct supergravity models with a single superfield describing inflation as well as the tiny cosmological constant $V \sim 10^{{-120}}$. One could expect that the simplest way to do it is to study models with a supersymmetric Minkowski vacuum and then slightly uplift them. However, due to the recently proven no-go theorem, such a tiny uplifting cannot be achieved by a small modification of the parameters of the theory. We illustrate this general result by investigation of models with a single chiral superfield recently proposed by Ketov and Terada. We show that the addition of a small constant or a linear term to the superpotential of a model with a stable supersymmetric Minkowski vacuum converts it to an AdS vacuum, which results in a rapid cosmological collapse. One can avoid this problem and uplift a supersymmetric Minkowski vacuum to a dS vacuum with $V_{0}\sim 10^{-120}$ without violating the no-go theorem by making these extra terms large enough. However, we show that this leads to a strong supersymmetry breaking in the uplifted vacua.