A new perspective on supersymmetric inflation

TL;DR

This paper explores a supersymmetric hybrid inflation model where dissipative effects from trigger field decay can solve the eta problem and generate significant curvature perturbations through modulated inflation.

Contribution

It introduces a novel mechanism where dissipation from trigger field decay alleviates the eta problem and produces curvature perturbations without extra symmetries.

Findings

Dissipative damping can dominate inflaton friction during inflation.

The mechanism naturally solves the eta problem in supersymmetric inflation.

Modulated inflation can generate significant curvature perturbations.

Abstract

We consider supersymmetric inflation with the hybrid-type potential. In the absence of the symmetry that forbids Hubble-induced mass terms, the inflaton mass will be as large as the Hubble scale during inflation. We consider gravitational decay of the trigger field as the least decay mode and find that the damping caused by the dissipation can dominate the friction of the inflaton when the heavy trigger field is coupled to the inflaton. The dissipative damping provides a solution to the traditional $\eta$ problem without introducing additional symmetry and interactions. Considering the spatial inhomogeneities of the dissipative coefficient, we find that modulated inflation (modulation of the inflaton velocity) can create significant curvature perturbations.