Is F-term hybrid inflation natural within minimal supersymmetric SO(10)?

TL;DR

This paper investigates the feasibility of embedding F-term hybrid inflation within minimal SO(10) models, finding that additional scalar fields are necessary to achieve natural inflation, which complicates the model's simplicity.

Contribution

The study demonstrates that minimal SO(10) models cannot naturally support F-term hybrid inflation without introducing extra scalar fields.

Findings

Standard Model singlets in minimal SO(10) cannot serve as inflatons.

Adding an extra scalar field enables flat directions and stable inflationary valleys.

Natural embedding of inflation in minimal SO(10) is challenging without extensions.

Abstract

We examine whether F-term supersymmetric hybrid inflation can be embedded within the minimal SO(10) model, in a natural way. We show that none of the singlets of the Standard Model symmetries in the minimal set of SO(10) representations can satisfy the conditions which are necessary for a scalar field to play the role of the inflaton. As a consequence, one has to introduce an extra scalar field, which however may spoil the naturalness of inflation within the context of SO(10). Nevertheless, if we add an extra scalar field, we are then able to construct a model that can accommodate flat directions while it preserves the stability of the inflationary valley.