Quasinormal modes of a rotating loop quantum black hole

TL;DR

This paper studies the quasinormal modes of a rotating loop quantum black hole, revealing how quantum corrections and rotation influence oscillation frequencies and decay rates, with implications for gravitational-wave observations.

Contribution

It introduces a method to compute quasinormal modes of a rotating loop quantum black hole, analyzing quantum and rotational effects on the spectrum, which was not previously explored.

Findings

Quantum corrections decrease oscillation frequency and damping rate.

Rotation causes nontrivial modulation of frequencies and damping.

Overtone signatures persist but shift with rotation and quantum effects.

Abstract

We investigate the quasinormal modes of a massless scalar field on an effective rotating loop quantum black hole background, constructed from a covariant spherical model via an improved Newman-Janis algorithm. Using the continued fraction method, we compute the spectrum for both fundamental and overtone modes, and systematically analyze how the frequencies depend on the quantum correction, spin, and angular structure of the perturbation. For all fundamental modes, increasing the quantum gravity correction monotonically reduces both the oscillation frequency and the damping rate, signaling slower oscillations and prolonged decay. Rotation imprints a nontrivial modulation: for a spherically symmetric perturbation, the real frequency displays a crossover as the spin grows, whereas this feature is suppressed once angular momentum is turned on; further activating the azimuthal component enhances the frequency and reduces the damping even more strongly. In the overtone sector, the rotating solution retains the hallmark quantum gravitational signatures of the spherical case - overtone outbursts and non-monotonic evolution - with rotation shifting these phenomena to weaker quantum corrections. Nonzero orbital angular momentum suppresses the outbursts, while the azimuthal degree of freedom boosts the frequency, giving rise to novel spectral inversions among higher overtones. Our results confirm that the effective rotating metric captures essential loop quantum gravity features, providing clear theoretical benchmarks for black hole spectroscopy and future gravitational-wave observations.