Quasinormal spectrum in the asymptotically safe gravity

TL;DR

This paper investigates how quantum corrections in asymptotically safe gravity affect black hole quasinormal modes, revealing significant deviations in higher overtones due to strong near-horizon quantum effects.

Contribution

It introduces three models of black holes in asymptotically safe gravity and analyzes their quasinormal spectra, highlighting the differing deviations from Schwarzschild modes.

Findings

Fundamental mode deviations are a few percent from Schwarzschild.

Higher overtones deviate by hundreds of percent.

Quantum corrections are strongest near the horizon and diminish rapidly with distance.

Abstract

Asymptotically safe gravity is based on the idea of the dependence of the gravitational coupling upon the distance from the origin, approaching its classical value in the weak field regime. We consider three cases of identifying the cut-off parameter in the asymptotically safe gravity, leading to the three distinctive models for black holes. We find that the deviation of the fundamental mode from the Schwarzschild limit is a few percent, in contrast to the higher overtones, where the deviation reaches hundreds of percent, even when the fundamental mode almost coincides with the Schwarzschild mode. This behavior is connected with the fact that the quantum correction to the black hole spacetime is strong near the event horizon, but quickly falls off with distance and negligible near the peak of the effective potential surrounding the black hole.