Contraints on Matter from Asymptotic Safety

TL;DR

This paper investigates how the presence of massless matter fields influences the ultraviolet fixed point in asymptotically safe gravity, establishing bounds on matter types and quantities to maintain the fixed point.

Contribution

It analyzes the impact of matter fields on the asymptotic safety fixed point in gravity, deriving bounds on matter content for the theory's consistency.

Findings

Existence of a UV attractive fixed point constrains matter field types.

Bounds on the number of matter fields compatible with asymptotic safety.

Implications for matter content in quantum gravity models.

Abstract

Recent studies of the ultraviolet behaviour of pure gravity suggest that it admits a non-Gaussian attractive fixed point, and therefore that the theory is asymptotically safe. We consider the effect on this fixed point of massless minimally coupled matter fields. The existence of a UV attractive fixed point puts bounds on the type and number of such fields.