Inflation, de Sitter Landscape and Super-Higgs effect

TL;DR

This paper develops supergravity-based cosmological models with nilpotent superfields that unify inflation and dark energy, allowing flexible parameter fitting and avoiding problematic light moduli.

Contribution

It introduces a class of models with spontaneous supersymmetry breaking and positive cosmological constant, simplifying fermionic interactions and enabling broad parameter control.

Findings

Models fit inflationary parameters n_s and r

Achieve controllable supersymmetry breaking levels

Avoid light moduli problems in supergravity

Abstract

We continue developing cosmological models involving nilpotent chiral superfields, which provide a simple unified description of inflation and the current acceleration of the universe in the supergravity context. We describe here a general class of models with a positive cosmological constant at the minimum of the potential, such that supersymmetry is spontaneously broken in the direction of the nilpotent superfield $S$. In the unitary gauge, these models have a simple action where all highly non-linear fermionic terms of the classical Volkov-Akulov action disappear. We present masses for bosons and fermions in these theories. By a proper choice of parameters in this class of models, one can fit any possible set of the inflationary parameters $n_{s}$ and $r$, a broad range of values of the vacuum energy $V_{0}$, which plays the role of the dark energy, and achieve a controllable level of supersymmetry breaking. This can be done without introducing light moduli, such as Polonyi fields, which often lead to cosmological problems in phenomenological supergravity.