相关论文: Optical phenomena in brany Kerr spacetimes

We investigate the tidal forces exerted by a spherically symmetric static parametrized black hole. Our analysis reveals that the radial and angular components of the tidal forces exerted by the black hole can exhibit both positive and…

Accretion disk reflection spectra, including broad iron emission lines, bear the imprints of the strong Doppler shifts and gravitational red-shifts close to black holes. The extremity of these shifts depends on the proximity of the…

Exact formulas relating the radii of the spherical photon orbits to the black hole's rotation parameter and the effective inclination angle of the orbit have been known only for equatorial and polar orbits up to now. Here we provide exact…

We study scattering of polarized light by a rotating (Kerr) black hole of the mass M and the angular momentum J. In order to keep trace of the polarization dependence of photon trajectories one can use the following dimensionless parameter:…

Black bounces are compact objects that combine the structures of regular black holes with those of wormholes. These spacetimes exhibit a rich causal structure and can differ fundamentally from usual black holes. In this work, we study the…

Interpreting horizon-scale observations of astrophysical black holes demands a general understanding of null geodesics in the Kerr spacetime. These may be divided into two classes: "direct" rays that primarily determine the observational…

The data from the event horizon telescope have provided a novel view of the vicinity of the horizon of a black hole (BH), by imaging the region around the light-ring. They have also raised hopes for measuring in the near future, features of…

A black hole casts a shadow as an optical appearance because of its strong gravitational field. We study how to determine the spin parameter and the inclination angle by observing the apparent shape of the shadow, which is distorted mainly…

We consider the escape probability of a photon emitted from the innermost stable circular orbit (ISCO) of a rapidly rotating black hole. As an isotropically emitting light source on a circular orbit reduces its orbital radius, the escape…

In this paper, we first investigate some aspects of frame dragging in strong gravity. The computations are carried out for the Kerr black hole and for the rotating Janis-Newman-Winicour solution, that is known to have a naked singularity on…

We discuss the conditions under which plane electromagnetic and gravitational waves can be amplified by a rotating black hole due to superradiant scattering. We show, in particular, that amplification can occur for low-frequency waves with…

We consider a rapidly spinning black hole surrounded by an equatorial, geometrically thin, slowly accreting disk that is stationary and axisymmetric. We analytically compute the broadening of electromagnetic line emissions from the…

We discuss the observational consequences of black hole spin in X-ray binaries within the framework of the standard thin accretion disk model. When compared to theoretical flux distribution from the surface of a thin disk surrounding a Kerr…

We model two temperature viscous accretion flows in the sub-Keplerian, optically thin, regime around rotating black holes including important radiation effects self-consistently. The model successfully explains observed luminosities from…

In this work, we show that regular black holes in a Randall-Sundrum-type brane world model are generated by the nonlocal bulk influence, expressed by a constant parameter in the brane metric, only in the spherical case. In the axial case…

The discovery of frame-dragging effects in binary pulsar timing experiments requires a compact companion with sufficiently large spin. A pulsar orbiting a fast rotating black hole could provide an appropriate test system. In this paper we…

We study spherically symmetric magnetically charged generic black hole solutions of general relativity coupled to non-linear electrodynamics (NED). For characteristic values of the generic spacetime parameters we give the position of…

We study the deflection angle of a light ray as it traverses on the equatorial plane of a charged spinning black hole. We provide detailed analysis of the light ray's trajectory, and derive the closed-form expression of the deflection angle…

Given the absence of observations of black hole binaries, it is critical that the full range of accessible parameter space be explored in anticipation of future observation with gravitational wave detectors. To this end, we compile the…

Binary black holes emit gravitational waves as they inspiral towards coalescence. Searches for electromagnetic counterparts to these gravitational waves rely on looking for common sources producing both signals. In this paper, we take a…