Dust collapse in asymptotic safety: a path to regular black holes

TL;DR

This paper explores how quantum gravity effects modeled by asymptotic safety can lead to regular, non-singular black holes formed via dust collapse, with a focus on the interior geometry and matter coupling.

Contribution

It introduces a novel model of regular black holes derived from effective quantum gravity, ensuring singularity avoidance during gravitational collapse.

Findings

The interior matter interacts with geometry through a coupling function derived from asymptotic safety.

The resulting spacetime remains free of singularities at all times.

The exterior geometry is determined by junction conditions, ensuring a consistent global structure.

Abstract

Regular black hole spacetimes are obtained from an effective Lagrangian for Quantum Einstein Gravity. The interior matter is modeled as a dust fluid, which interacts with the geometry through a multiplicative coupling function denoted as $\chi$. The specific functional form of $\chi$ is deduced from Asymptotically Safe gravity, under the key assumption that the Reuter fixed point remains minimally affected by the presence of matter. As a consequence the gravitational coupling vanishes at high energies. The static exterior geometry of the black hole is entirely determined by the junction conditions at the boundary surface. Consequently, the resulting global spacetime geometry remains devoid of singularities at all times. This outcome offers a new perspective on how regular black holes are formed through gravitational collapse.