Asymptotic safety in an interacting system of gravity and scalar matter

TL;DR

This paper investigates the possibility of asymptotic safety in a quantum gravity system coupled with scalar matter, analyzing fixed points and anomalous dimensions to understand the theory's consistency at high energies.

Contribution

It extends asymptotic safety analysis to include scalar matter interactions and examines the fixed points and metric fluctuation components in this context.

Findings

Viable fixed point found in pure gravity system.

Indications of asymptotic safety in matter-gravity interactions.

Significant differences in anomalous dimensions between metric components.

Abstract

Asymptotic safety is an attractive scenario for the dynamics of quantum spacetime. Here, we work from a phenomenologically motivated point of view and emphasize that a viable dynamics for quantum gravity in our universe must account for the existence of matter. In particular, we explore the scale-dependence of a scalar matter-gravity-vertex, and investigate whether an interacting fixed point exists for the so-defined Newton coupling. We find a viable fixed point in the pure-gravity system, disregarding scalar quantum fluctuations. We explore its extensions to the case with dynamical scalars, and find indications of asymptotic safety in the matter-gravity system. We moreover examine the anomalous dimensions for different components of the metric fluctuations, and find significant differences between the transverse traceless and scalar component.