Related papers: Polarized image of a rotating black hole in Scalar…
Inspired by the observations of supermassive black hole M87* in \emph{Event Horizon Telescope }(EHT) experiment, a remarkable surge in black hole physics is to use the black hole shadow's observables to distinguish general relativity (GR)…
We present an analytic study of the mode-coupling phenomena for a scalar field propagating on a rotating Kerr background. Physically, this phenomena is caused by the dragging of reference frames, due to the black-hole (or star's) rotation.…
We consider general perturbations of a Schwarzschild black holes in the context of f(R) gravity. A reduced set of frame independent master variables are determined, which obey two closed wave equations - one for the transverse, trace-free…
Variable active galactic nuclei showing periodic light curves have been proposed as massive black hole binary (MBHB) candidates. In such scenarios the periodicity can be due to relativistic Doppler-boosting of the emitted light. This…
Polarization measurements provide strong constraints on models for emission from rotation-powered pulsars. We present multiwavelength polarization predictions showing that measurements over a range of frequencies can be particularly…
The strong gravitational lensing of a regular and rotating magnetic black hole in non-minimally coupled Einstein-Yang-Mills theory is studied. We find that, with the increase of any characteristic parameters of this black hole, such as the…
Within the framework of metric-affine gravity (MAG, metric and an independent linear connection constitute spacetime), we find, for a specific gravitational Lagrangian and by using {\it prolongation} techniques, a stationary axially…
Trajectory of a test particle or a photon around a general spherical black hole is studied and bending of light trajectory is investigated. Pseudo-Newtonian gravitational potential describing the gravitational field of the black hole is…
In the present work the rotation of polarization vector due to the gravitational field of a rotating body has been derived, from the general expression of Maxwell's equation in the curved space-time. Considering the far field approximation…
With the help of AdS/CFT correspondence, we analyze the holographic Einstein images via the response function of the complex scalar field as a probe wave on the AdS Schwarzschild scalar-tensor-vector gravity (STVG) black hole (BH). We find…
Models of the resolved Event Horizon Telescope (EHT) sources Sgr A* and M87* are constrained by observations at multiple wavelengths, resolutions, polarizations, and time cadences. In this paper we compare unresolved circular polarization…
We analyze the generalized spin precession of a test gyroscope around a stationary spacetime i.e. for Kerr-MOG black hole~(BH) in scalar-tensor-vector gravity or modified gravity~(MOG). A detailed study of generalized spin frequency has…
In this study, we investigate rotating black hole solutions within a scalar Gauss-Bonnet gravity framework that incorporates a squared Gauss-Bonnet term. By employing a quadratic exponential coupling function between the scalar field and…
The recent detection of gravitational waves from black hole coalescences and the first image of the black hole shadow enhance the possibilities of testing gravitational theories in the strong-field regime. In this paper, we study the…
We study a six-dimensional vector-tensor gravitation theory compactified to M_4 x S^2. Here, static spherically-symmetric solutions to the field equations of the theory are investigated. We examine the case that the magnetic charge of the…
Analytical models of magnetized, geometrically thick disks are relevant to understand the physical conditions of plasma around compact objects and to explore its emitting properties. This has become increasingly important in recent years in…
Merging binary black holes exhibit a ringdown phase in which they primarily emit gravitational waves in the shape of damped sinusoids corresponding to quasi-normal modes of the Kerr remnant. In general, each mode carries four degrees of…
Magnetic fields are believed to drive accretion and relativistic jets in black hole accretion systems, but the magnetic-field structure that controls these phenomena remains uncertain. We perform general relativistic (GR) polarized…
We study the gravitational lensing by a Kerr-Sen Black Hole arising in heterotic string theory. A closed form expression for the bending angle of light in equatorial plane of Kerr-Sen Black Hole is derived as a function of impact parameter,…
The images of supermassive black holes in M87 and our galaxy captured by the Event Horizon Telescope (EHT) might open up a new way for exploring black hole physics at the horizon scale. Theoretically, this could provide insights into…