Related papers: Light curve of a source orbiting around a black ho…
In this article, we considered the strong field approximation of nonlinear electrodynamics black hole and constructed its rotating counterpart by applying the modified Newman-Janis algorithm. The corresponding metric function in the strong…
The inner 20 gravitational radii around the black hole at the centre of luminous Active Galactic Nuclei and stellar mass Black Hole Binaries are now being routinely mapped by X-ray spectral-timing techniques. Spectral blurring and…
Clumps of material orbiting a black hole may be disturbed, somewhat like comets in the Kuiper belt, to relatively small periastron orbits. Each periastron passage changes the orbital parameters in such a way that the orbit becomes more and…
In this paper we study the light bending caused by a slowly rotating source in the context of quadratic theories of gravity, in which the Einstein--Hilbert action is extended by additional terms quadratic in the curvature tensors. The…
We examine optical V-band light curves in luminous eclipsing black hole X-ray binaries, using a supercritical accretion/outflow model that is more realistic than the formerly used ones. In order to compute the theoretical light curve in the…
The motion of photons around black holes determines the shape of shadow and match the ringdown properties of a perturbed black hole. Observations of shadows and ringdown waveforms will reveal the nature of black holes. In this paper, we…
In this paper, the shadows cast by Einstein-Maxwell-Dilaton-Axion black hole and naked singularity are studied. The shadow of a rotating black hole is found to be a dark zone covered by a deformed circle. For a fixed value of the spin $a$,…
General relativity makes clear predictions about the spacetime geometry around black holes. In the near future, new facilities will have the capability to explore the metric around SgrA$^*$, the supermassive black hole candidate at the…
A black hole's gravitational pull can deflect light rays to an arbitrary degree. As a result, any source fluctuation near the black hole creates multiple lagged images on an observer's screen. For optically thin stochastic emission, these…
We consider thin accretion disks in the field of a class of rotating regular black holes. For this purpose, we obtain the radius of the innermost stable circular orbit, $r_{ISCO}$ and efficiency of accretion disk in converting matter into…
Non-commutative corrections to the classical expression for the fuzzy sphere area are found out through the asymptotic expansion for its heat kernel trace. As an important consequence, some quantum gravity deviations in the luminosity of…
The dark matter accretion theory (around a central body) of the author on the basis of his 5-dimensional Projective Unified Field Theory (PUFT) is applied to the orbital motion of stars around the center of the Galaxy. The departure of the…
Simulated images of a black hole surrounded by optically thin emission typically display two main features: a central brightness depression and a narrow, bright "photon ring" consisting of strongly lensed images superposed on top of the…
We consider a particle moving towards a rotating black hole. We are interested in the number of its revolution $n$ around a black hole. In our previous work (Pavlov and Zaslavskii in Gen Relativ Gravit 50: 14, 2018. arXiv:1707.02860) we…
We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These…
Motivated by string theory scenarios, we study the optical aspect of AdS black holes in Einstein-Maxwell-dilaton theory. Concretely, we investigate and examine the shadows and the deflection angle of light rays by such cosmological black…
A black hole image contains a bright ring of photons that have closely circled the black hole on their way from the source to the detector. Here, we study the photon ring of a rotating black hole which is pierced by a global hyper-light…
Massive objects orbiting a near-extreme Kerr black hole quickly plunge into the horizon after passing the innermost stable circular orbit. The plunge trajectory is shown to be related by a conformal map to a circular orbit. Conformal…
The light deflection under a strong gravitational field, referred to as strong gravitational lensing, provides a powerful probe of spacetime geometry. Besides, laboratory analogue models are employed to study the effects of curved spacetime…
The $n=1$ photon ring is a full image of the astrophysical source around a black hole, produced by photons that execute $n\approx1$ half-orbit around the event horizon on their way to an observer. The Black Hole Explorer (BHEX) is a…