No-scale hybrid inflation with R-symmetry breaking

TL;DR

This paper develops a no-scale supergravity hybrid inflation model with maximal R-symmetry breaking, analyzing inflation dynamics, reheating, and connections to GUT scales, while considering SUSY breaking and moduli effects.

Contribution

It introduces a novel no-scale supergravity hybrid inflation scenario with R-symmetry breaking and explores its implications for inflation, reheating, and GUT-scale physics.

Findings

Effective inflation potential is asymptotically flat.

Reheating is unaffected by R-symmetry breaking.

Connection established between inflation, R-symmetry breaking, and GUT scales.

Abstract

In this paper we provide a no-scale supergravity scenario of hybrid inflation with R-symmetry being broken maximally. We investigate the inflation dynamics in details in both cases of pure F-term hybrid inflation and when adding constant Fayet-Iliopoulos D-terms. The effective inflation potential is asymptotically flat in a region of the parameter space in both cases. We explore all regions in the parameter space when discussing the constraints from the observables. We point out a connection between inflation, R-symmetry breaking and GUT scales. The moduli backreaction and SUSY breaking effects are investigated in a specific stabilization mechanism. We emphasis that a successful reheating is not affected by R-symmetry breaking, but it has interesting consequences. We study the reheating in flipped GUT model. We argue in favor of $Z_2$ symmetry associated with flipped GUT models to avoid phenomenologically dangerous operators and allow for decay channels for the inflaton to right-handed neutrinos (sneutrinos).