Cosmological Attractors and Asymptotic Freedom of the Inflaton Field

TL;DR

This paper demonstrates that in cosmological $eta$-attractor models, the inflaton's interactions are exponentially suppressed during inflation due to hyperbolic geometry, ensuring potential flatness and stability.

Contribution

It reveals the geometric origin of inflaton coupling suppression in supergravity $eta$-attractors, linking moduli space geometry to inflationary dynamics.

Findings

Inflaton coupling to other fields is exponentially suppressed during inflation.

Hyperbolic geometry of moduli space underpins the flatness of the inflaton potential.

Protection of potential flatness is due to geometric features in supergravity models.

Abstract

We show that the inflaton coupling to all other fields is exponentially suppressed during inflation in the cosmological $\alpha$-attractor models. In the context of supergravity, this feature is a consequence of the underlying hyperbolic geometry of the moduli space which has a flat direction corresponding to the inflaton field. A combination of these factors protects the asymptotic flatness of the inflaton potential.