Cosmological bounds on the field content of asymptotically safe gravity-matter models

TL;DR

This paper explores how non-Gaussian fixed points in gravity-matter systems influence inflationary models, showing compatibility with cosmological data when matter content resembles the standard model, highlighting the importance of the fixed point's properties.

Contribution

It demonstrates that NGFPs in gravity-matter systems with standard model-like matter content can produce cosmologically viable inflationary models, emphasizing the role of fixed point characteristics.

Findings

NGFPs compatible with standard model matter content

Negative fixed point value of cosmological constant is crucial

Models align with cosmological observations

Abstract

We use the non-Gaussian fixed points (NGFPs) appearing in the renormalization group flow of gravity and gravity-matter systems to construct models of NGFP-driven inflation via a renormalization group improvement scheme. The cosmological predictions of these models depend sensitively on the characteristic properties of the NGFPs, including their position and stability coefficients, which in turn are determined by the field content of the underlying matter sector. We demonstrate that the NGFPs appearing in gravity-matter systems where the matter content is close to the one of the standard model of particle physics are the ones compatible with cosmological data. Somewhat counterintuitively, the negative fixed point value of the dimensionless cosmological constant is essential for these findings.