Related papers: Accelerating black holes: quasinormal modes and la…
We study scalar test-field perturbations on top of a Kerr--black-bounce background, i.e. a family of rotating regular black holes and/or rotating traversable wormholes that can mimic Kerr black holes. We compute the quasi-normal modes for a…
We study the propagation of scalar fields in the background of an asymptotically de-Sitter black hole solution in $f(R)$ gravity. The aim of this work is to analyze in modified theories of gravity the existence of an anomalous decay rate of…
In this paper we investigate how a regular scale-dependent black hole, characterized by a single extra parameter $\epsilon$, behaves under perturbations by a test field (quasi-normal modes) and under light imaging (shadows) in a…
Recently, black hole models in a nonlinear modification of the Maxwell electrodynamics were suggested, possessing simultaneously properties of an extreme charge and regularity (Bronnikov K. A., Phys. Rev. D, 110 (2024) 024021). We study…
Regular black holes, nonsingular solutions to gravitational collapse with quantum corrections, offer a compelling alternative to classical black holes with curvature singularities. In this work, we investigate how the presence of skewed…
We present a short review of the analytical aspects of recent progress in the study of black hole spectral instability and its potential observational consequences. This topic, inspired by earlier foundational works, has attracted…
In the galactic core, when the scale of dark matter is small, the distribution of dark matter is that of a constant density dark matter core.Considering the case of a supermassive black hole coupled to a constant density dark matter core,…
The quasinormal mode spectrum of black holes is unstable against small modifications of the radial potential describing massless perturbations. We study how these small modifications affect the convergence of the quasinormal mode expansion…
The presence of extra dimensions generically modify the spacetime geometry of a rotating black hole, by adding an additional hair, besides the mass $M$ and the angular momentum $J$, known as the `tidal charge' parameter, $\beta$. In a…
We generalize the Chern-Simons modified gravity to the metric-affine case and impose projective invariance by supplementing the Pontryagin density with homothetic curvature terms which do not spoil topologicity. The latter is then broken by…
We study quasinormal modes of massive scalar and massless Dirac fields in the background of regular black holes and traversable wormholes arising in Covariant Effective Quantum Gravity. Using both the JWKB approximation and time-domain…
We have studied quasinormal modes of scalar perturbations of a black hole in massive gravity. The parameters of the theory, such as the mass of the black hole, the scalar charge of the black hole and the spherical harmonic index is varied…
In this work, we have studied the quasinormal modes of a black hole in a model of the type $f(Q)=\underset{n}{\sum}a_{n}\left(Q-Q_{0}\right)^{n} $ in $f(Q)$ gravity by using a recently introduced method known as Bernstein spectral method…
Based on the hyperboloidal framework, we research the dynamical process of charged de Sitter black holes scattered by a charged scalar field. From the linear perturbation analysis, with the coupling strength within a critical interval, the…
Realistic black holes are usually dynamical, noticeable or sluggish. The Vaidya metric is a significant and tractable model for simulating a dynamical black hole. In this study, we consider scalar perturbations in a dynamical Vaidya black…
We study perturbations of black holes absorbing dark energy. Due to the accretion of dark energy, the black hole mass changes. We observe distinct perturbation behaviors for absorption of different forms of dark energy into the black holes.…
After black holes collide, the remnant settles to a stationary state by emitting gravitational waves. Once non-linearities subside, these ringdown waves are dominated by exponentially-damped sinusoids, or quasinormal modes. We develop a…
We first show that the master equations for massless perturbations of accelerating rotating black holes can be transformed into the Heun's equation. The quasinormal modes of the black holes can be easily calculated in the framework of the…
Massive scalar fields can form long-lived configurations around black holes. These configurations, dubbed quasi-bound states, have been studied both in the linear and nonlinear regimes. In this paper we show that quasi-bound states can form…
We study numerically the fully nonlinear gravitational collapse of a self-gravitating, minimally-coupled, massless scalar field in spherical symmetry. Our numerical code is based on double-null coordinates and on free evolution of the…