Cosmological Inflation with orbifold moduli as inflatons

TL;DR

This paper investigates inflation driven by orbifold moduli as inflatons, analyzing superpotentials for modular invariance, and finds limited slow-roll inflation with some models achieving up to 20 e-folds.

Contribution

It introduces models of cosmological inflation using orbifold moduli as inflatons with modular invariant superpotentials, highlighting challenges in achieving sufficient slow-roll conditions.

Findings

Most models do not produce a flat enough potential for slow roll.

A specific model achieves up to 20 e-folds of inflation.

Inflation ends in a non-supersymmetric minimum.

Abstract

Cosmological inflation is studied in the case where the inflaton is the overall modulus $T$ for an orbifold. General forms of the (non-perturbative) superpotential are considered to ensure that $G=K+{\rm ln}|W|^2$ is modular invariant. We find generically that these models do not produce a potential flat enough for slow roll to a supersymmetric minimum, although we do find a model which produces up to 20 e-folds of inflation to a non-supersymmetric minimum.