Quasinormal modes of charged black holes in Asymptotically Safe Gravity

TL;DR

This paper computes the quasinormal modes of scalar and neutrino perturbations around charged black holes in Asymptotically Safe Gravity, revealing how charge and coupling influence the spectrum and providing an analytic formula in the high-frequency limit.

Contribution

It presents new calculations of quasinormal modes in this gravity model, correcting previous numerical errors and deriving an explicit analytic formula in the eikonal limit.

Findings

Charge and coupling significantly alter quasinormal spectra.

Previous scalar mode calculations contained large numerical errors.

Analytic formula in the high-frequency limit confirms geodesic correspondence.

Abstract

We calculate quasinormal modes of scalar and neutrino perturbations around the charged black hole in Asymptotically Safe Gravity. We show that the charge and coupling constant change the quasinormal spectrum considerably. We show that previous calculations of scalar quasinormal modes in this background [F. Javed, Phys. Dark Univ., 44, 101450 (2024)] suffer from a large numerical error exceeding the effect, that is, the deviations of the frequencies from their Schwarzschild limits. In the high frequency (eikonal) limit an explicit analytic formula for quasinormal modes is derived, which confirms the correspondence between the null circular geodesics and eikonal quasinormal frequencies.