Searcharxiv⌕ Search

arXiv · 2610.00393

Quasinormal Modes of Reissner-Nordström Black Holes in Modified Gravity

Abstract

In the framework of Scalar-Tensor-Vector Gravity (STVG), this paper investigates the quasinormal modes and time-domain evolution of Reissner-Nordström Modified Gravity (MOG) black holes under massless scalar, electromagnetic, and gravitational perturbations. Quasinormal frequencies are calculated by extending the 3rd- to 6th-order WKB method and combining it with Padé approximation to the 13th order, while complete time-domain waveforms are obtained using a finite-difference method based on light-cone coordinates. The results indicate that increasing the MOG parameter $α$ raises the effective mass of the black holes, leading to a decrease in the damping rate $|ω_I|$ and a slower ringdown decay. An increase in charge $Q$ produces a similar effect, with the damping approaching zero in the near-extremal limit. Regarding the ringdown decay times for the three types of perturbations, the gravitational field has the longest duration, the electromagnetic field is intermediate, and the scalar field is the shortest. The oscillations and decay observed in the time-domain waveforms are qualitatively consistent with the frequency-domain results, and the power-law exponent governing the late-time tail aligns with that of asymptotically flat spacetimes. This study provides a systematic theoretical reference for testing modified gravity theories using black hole spectroscopy.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Xia-Tong Tan, Yu Zhang, Zhi-Hong Nie. 2026-09-30. Quasinormal Modes of Reissner-Nordström Black Holes in Modified Gravity. https://arxiv.org/abs/2610.00393

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Introduction to the ADM formalism

The authors present concepts and mathematical developments which give rise to the Hamiltonian formulation of Einstein's general relativity, first introduced by Arnowitt, Deser, and Misner. All the geometrical quantities needed for the construction are explicitly obtained, and examples of some of the application of the formalism are given.

gr-qc↗

Group averaging and the geometry of physical quantum states: from normalizable solutions to solvable loop quantum cosmology

In canonical quantum gravity the physical states solve the constraints but are typically not normalizable in the kinematical Hilbert space. Group averaging constructs them from normalizable kinematical seeds. We describe the geometry of this seed-to-state map in the language of geometric quantum mechanics. When averaging is an orthogonal projection, the admissible kinematical rays form a holomorphic vector bundle over the physical ray space. The embedded exact solutions form its zero section, and its fibers are strictly larger than gauge orbits. Observables descend to the base exactly when the Hessian of the squared constraint vanishes along their flow. For distributional physical states, group averaging on an explicit Sobolev test space yields an affine bundle of representatives. Its sections are embeddings of the physical ray space whose images contain no exact solutions. The test-space inner product singles out one of them, and narrowing the seed profile gives Weyl sequences of approximate solutions. We apply this to solvable loop quantum cosmology. Group averaging reproduces the Klein--Gordon physical inner product on an explicit test space. Because the scalar-field momentum enters the constraint quadratically, the constraint spectrum has an edge near the shell. The canonical section is then mode-dependent and not Kähler isometric, and the canonical seeds of small universes are biased off the shell. The edge also separates the Page--Wootters state from the slice of the Klein--Gordon solution. An ideal clock shows none of these effects. The results separate the canonical structures, namely physical rays, physical geometry and Dirac observables, from those that depend on a choice of seeds, test space or clock.

gr-qc↗

Gravitational baryogenesis in Gauss-Bonnet braneworld cosmology

The present study investigates the feasibility of gravitational baryogenesis in a Gauss-Bonnet (GB) modified Randall-Sundrum (RS) type II braneworld cosmology. The modified expansion rate of the Universe in this scenario evolves through three distinct expansion regimes, the GB regime at early times where the expansion rate $H \sim ρ^{1/3}$ falls more slowly than the standard expansion law $H\sim ρ^{1/2}$ of GR, then the RS type era with an enhanced expansion $H \sim ρ$, before finally reducing to the standard expansion law in the low energy limit. Gravitational baryogenesis depends on $\dot{R}$ and requires $\dot{R} <0$. This condition is satisfied for the GB and GR regimes. However, $\dot{R}>0$ for the RS regime and successful baryogenesis requires either that the decoupling temperature occurs during the GB regime or that the Universe makes a direct transition from the GB regime to the GR regime. The GB baryon asymmetry $η(T)$ is proportional to $μ(1+w)(1-w)(1+1/β)$, where $μ$ is the energy scale $μ\equiv 1/l$ associated with the bulk curvature scale $l$, $β\equiv 4 αμ^{2}$, where $α$ is the GB coupling, and $w$ is the equation of state parameter $p=w ρ$. Studies of inflation in GB-braneworld cosmology place constraints on the allowed ranges of the parameters $μ$ and $β$. Guided by these, the asymmetry has been calculated for ranges of $(μ, β, w)$ and it is found that the observed values can be obtained for a value of $β$ within the range $(10^{-2} - 10^{-3})$ for $μ=10^{12}$ GeV, and within the range $(10^{-1}- 10^{-2})$ for $μ=10^{13}$ GeV. All values of $η$ for $μ=10^{14}$ are too high. In contrast to GR where $η$ is zero for a radiation dominated Universe ($w=1/3$), it is non-zero in GB braneworld cosmology.

gr-qc↗