Superconformal Subcritical Hybrid Inflation

TL;DR

This paper explores a novel superconformal supergravity model of hybrid inflation that operates in the subcritical regime, producing predictions aligned with Planck 2015 data and resembling alpha attractor potentials.

Contribution

It introduces a new inflationary scenario within superconformal supergravity that occurs in the subcritical regime, expanding the landscape of viable inflation models.

Findings

Predictions for scalar spectral index and tensor-to-scalar ratio match Planck 2015 results.

The potential in the subcritical regime resembles alpha attractor models.

Demonstrates the viability of subcritical hybrid inflation in superconformal frameworks.

Abstract

We consider D-term hybrid inflation in the framework of superconformal supergravity. In part of the parameter space, inflation continues for subcritical inflaton field value. Consequently, a new type of inflation emerges, which gives predictions for the scalar spectral index and the tensor-to-scalar ratio that are consistent with the Planck 2015 results. The potential in the subcritical regime is found to have a similar structure to one in the simplest class of superconformal alpha attractors.