Related papers: On the approximate relation between black-hole per…
The deviations of non-linear perturbations of black holes from the linear case are important in the context of ringdown signals with large signal-to-noise ratio. To facilitate a comparison between the two we derive several results of linear…
Black hole perturbation theory is useful for studying the stability of black holes and calculating ringdown gravitational waves after the collision of two black holes. Most previous calculations were carried out at the level of the field…
The ringdown of a perturbed black hole contains fundamental information about space-time in the form of Quasi Normal Modes (QNM). Modifications to general relativity, or extended profiles of other fields surrounding the black hole, so…
We try to identify the sources and systematics of the uncertainty of the masses of the central black holes in active galactic nuclei (AGNs) which have been obtained by reverberation-mapping methods. We characterize the broad H$\beta$…
We investigate a slowly rotating black hole solution in a novel Einstein-Maxwell-scalar theory, which is prompted by the classification of general Einstein-Maxwell-scalar theories. The gyromagnetic ratio of this black hole is calculated,…
In \cite{Bahamonde:2019zea}, a spherically symmetric black hole (BH) was derived from the quadratic form of $f(T)$. Here we derive the associated energy, invariants of curvature, and torsion of this BH and demonstrate that the higher-order…
For a brief moment, a binary black hole (BBH) merger can be the most powerful astrophysical event in the visible universe. Here we present a model fit for this gravitational-wave peak luminosity of nonprecessing quasicircular BBH systems as…
We analyze numerical-relativity (NR) waveforms that cover nine orbits (18 gravitational-wave cycles) before merger of an equal-mass system with low eccentricity, with numerical uncertainties of 0.25 radians in the phase and less than 2% in…
In calculations of the inspiral of binary black holes an intermediate approximation is needed that can bridge the post-Newtonian methods of the early inspiral and the numerical relativity computations of the final plunge. We describe here…
We compute the gravitational waveform emitted during the transition from quasi-spherical inspiral to plunge, merger and ringdown for a system of two black holes in the extreme mass ratio limit, where the primary is spinning and the…
The coalescence of the most massive black hole (MBH) binaries releases gravitational waves (GWs) within the detectable frequency range of Pulsar Timing Arrays (PTAs) $(10^{-9} - 10^{-6})$ Hz. The incoherent superposition of GWs from MBH…
Inspired by the quark-antiquark confinement potential, Mazharimousavi et al. \cite{Mazharimousavi:2023okd} proposed a nonlinear electrodynamics (NED) model, and based on this model, they constructed a charged black hole solution that…
We investigate the effects of the Gauss-Bonnet (GB) gravitational trace anomaly on the circular motion of test particles around black holes (BHs) and its implications for quasi-periodic oscillations (QPOs) in various theoretical models.…
Primordial Black Holes (PBHs) may have formed in the early Universe due to the collapse of super-horizon curvature fluctuations. Simulations of PBH formation have been essential for inferring the initial conditions that lead to black hole…
We use the open source, community-driven, numerical relativity software, the Einstein Toolkit to study the physics of eccentric, spinning, nonprecessing binary black hole mergers with mass-ratios $q=\{2, 4, 6\}$, individual dimensionless…
We present the frequency-domain quasi-circular precessing binary-black-hole model PhenomXPNR. This model combines the most precise available post-Newtonian description of the evolution of the precession dynamics through inspiral with…
The rapid advancement of gravitational wave astronomy in recent years has paved the way for the burgeoning development of black hole spectroscopy, which enhances the possibility of testing black holes by their quasinormal modes (QNMs). In…
The ringdown of a perturbed black hole consists of a superposition of quasi-normal modes (QNMs), with complex frequencies determined by the black hole's mass and spin, while phases and amplitudes depend on binary parameters. Traditional…
We propose a method of determining solutions to the constraint equations of General Relativity approximately describing binary black holes in quasi-stationary circular orbits. Black holes with arbitrary linear momenta are constructed in the…
During the last years, one had to combine the proposal about how quasinormal frequencies are related with black holes and the proposal about the adiabatic invariance of black holes in order to derive the quantized entropy spectrum and its…