Renormalization Group independence of Cosmological Attractors

TL;DR

This paper demonstrates that the inflationary predictions of a broad class of cosmological models called attractors remain stable under quantum corrections when analyzed with renormalization group techniques, ensuring their robustness.

Contribution

It shows that the inflationary parameters of $ ext{alpha}$- and $ ext{xi}$-attractors are nearly independent of the RG flow, confirming their quantum stability across models.

Findings

Inflationary predictions are RG invariant at quantum level.

The RG invariance holds under a generic condition on the renormalization scale.

Higgs inflation is a specific case where this invariance is confirmed.

Abstract

The large class of inflationary models known as $\alpha$- and $\xi$-attractors gives identical cosmological predictions at tree level (at leading order in inverse power of the number of efolds). Working with the renormalization group improved action, we show that these predictions are robust under quantum corrections. This means that for all the models considered the inflationary parameters $(n_s,r)$ are (nearly) independent on the Renormalization Group flow. The result follows once the field dependence of the renormalization scale, fixed by demanding the leading log correction to vanish, satisfies a quite generic condition. In Higgs inflation (which is a particular $\xi$-attractor) this is indeed the case; in the more general attractor models this is still ensured by the renormalizability of the theory in the effective field theory sense.