Cosmological Attractors from $\alpha$-Scale Supergravity

TL;DR

This paper introduces a new formulation of $ extalpha$-attractors in supergravity using a single chiral superfield, linking inflationary predictions to the curvature of the Kahler manifold and exploring their geometric limits.

Contribution

It presents a novel single-superfield formulation of $ extalpha$-attractors, connecting their inflationary behavior to Kahler geometry and deformations of no-scale models.

Findings

New single-superfield $ extalpha$-attractor models constructed.

De Sitter plateau with exponential fall-off achieved.

Connections between curved and flat Kahler geometries established.

Abstract

The Planck value of the spectral index can be interpreted as $n_s = 1 - 2/N$ in terms of the number of e-foldings $N$. An appealing explanation for this phenomenological observation is provided by $\alpha$-attractors: the inflationary predictions of these supergravity models are fully determined by the curvature of the Kahler manifold. We provide a novel formulation of $\alpha$-attractors which only involves a single chiral superfield. Our construction involves a natural deformation of no-scale models, and employs these to construct a De Sitter plateau with an exponential fall-off. Finally, we show how analogous structures with a flat Kahler geometry arise as a singular limit of such $\alpha$-scale models.