New developments in inflationary models

TL;DR

This paper explores inflationary models where the inflaton is a flat direction affected by gravity-mediated supersymmetry breaking, showing how its mass running enables slow roll inflation compatible with observations.

Contribution

It introduces a class of inflation models with a running inflaton mass due to couplings, expanding the understanding of inflation dynamics in supersymmetric frameworks.

Findings

Inflaton mass can decrease at lower scales, enabling slow roll inflation.

The spectral index becomes scale-dependent in these models.

Certain parameter regions align with current observational data.

Abstract

We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible couplings to other fields, its mass runs with scale and can reach the small value required by slow roll inflation at a lower scale, even if its initial value is too large. Slow roll inflation can therefore take place in such a regime, as long as the mass remains small, with a spectral index that is then scale dependent. We explore the parameter space of this kind of models to find the region compatible with the present observations.