Breaking of isospectrality of quasinormal modes in nonrotating loop quantum gravity black holes

TL;DR

This paper investigates how loop quantum gravity modifications affect the quasinormal modes of nonrotating black holes, revealing tiny deviations from classical predictions and the breaking of isospectrality, with implications for quantum gravity phenomenology.

Contribution

It provides the first detailed analysis of quasinormal modes in loop quantum gravity black holes, showing isospectrality breaking and quantifying deviations from classical results.

Findings

Deviations in quasinormal frequencies are tiny but detectable.

Isospectrality between axial and polar modes is broken.

Deviations decay as an inverse power law of black hole mass.

Abstract

We study the quasinormal frequencies of three effective geometries of nonrotating regular black holes derived from loop quantum gravity. Concretely, we consider the Ashtekar-Olmedo-Singh and two Gambini-Olmedo-Pullin prescriptions. We compute the quasinormal frequencies of axial and polar perturbations adopting a WKB method. We show that they differ from those of classical general relativity and, more importantly, that isospectrality is broken. Nevertheless, these deviations are tiny, even for microscopic black holes, and they decay following an inverse power law of the size of the mass of the black holes. For the sake of completeness, we also analyze scalar and vector perturbations, reaching similar conclusions.