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In this work, we study the emission of tensor-type gravitational degrees of freedom from a higher-dimensional, simply rotating black hole in the bulk. The decoupled radial part of the corresponding field equation is first solved…

High Energy Physics - Theory · Physics 2010-06-08 P. Kanti , Hideo Kodama , R. A. Konoplya , N. Pappas , A. Zhidenko

This work investigates observational properties, namely the shadow and photon ring structure, of emission profiles originating near compact objects. In particular, we consider a distorted and deformed compact object characterised by two…

High Energy Astrophysical Phenomena · Physics 2025-06-16 Shokoufe Faraji , João Luís Rosa

The apparent shadow of a black hole provides one of the most direct probes of strong-field general relativity. While the shadow size in asymptotically flat spacetimes is well understood, the influence of cosmic expansion on its apparent…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Debarshi Mukherjee

We investigate the impact of dark matter halos on the gravitational lensing produced by electrically charged, spherically symmetric black holes in the strong-field regime. The study focuses on two dark matter models: the Universal Rotation…

General Relativity and Quantum Cosmology · Physics 2025-01-17 Niyaz Uddin Molla , Himanshu Chaudhary , Salvatore Capozziello , Farruh Atamurotov , G. Mustafa , Ujjal Debnath

The quantum genesis of Hawking radiation is a long-standing puzzle in black hole physics. Semi-classically one can argue that the spectrum of radiation emitted by a black hole look very much sparse unlike what is expected from a thermal…

General Relativity and Quantum Cosmology · Physics 2016-02-05 Kinjalk Lochan , Sumanta Chakraborty

Images from the vicinity of the black hole horizon at the Galactic centre (Sgr A*) could be obtained in the near future with a Very Large Baseline Array of sub-millimetre telescopes. The recently observed short-term infrared and X-ray…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Abraham Loeb

Constraints on the geometry of a static spherically symmetric black hole are obtained by requiring the spacetime curvature to be analytic at the event horizon. For a zero temperature black hole further constraints are obtained by also…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Paul R. Anderson , Courtney D. Mull

We have studied photon motion around axially symmetric rotating Kerr black hole in the presence of plasma with radial power-law density. It is shown that in the presence of plasma the observed shape and size of shadow changes depending on…

General Relativity and Quantum Cosmology · Physics 2015-10-21 Farruh Atamurotov , Bobomurat Ahmedov , Ahmadjon Abdujabbarov

In this work, we investigate the shadow properties of the Kerr-Newman-Anti-de Sitter black hole coupled to a nonlinear electrodynamics. We construct the shadow by employing the celestial coordinate approach for observers located at finite…

General Relativity and Quantum Cosmology · Physics 2025-08-20 Mohsen Fathi

The Event Horizon Telescope (EHT) is providing unprecedented high-resolution images of supermassive black holes. These images are fundamentally related to properties of the luminous accretion disks, since black holes themselves produce no…

High Energy Astrophysical Phenomena · Physics 2026-02-13 Alexandra G. Guerrero , Daniel E. Holz

We consider non-commutating Simpson-Visser spacetime and study the superradiance phenomena and the shadow cast by the back hole associated with this modified spacetime. We extensively study the different aspects of the black hole associated…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Sohan Kumar Jha , Anisur Rahaman

The Event Horizon Telescope (EHT) Collaboration produced the first image of the apparent shadow of the central black hole of Sagittarius\,A$^*$ (\sgra). \sgra source structure varies significantly on timescales shorter than the duration of…

High Energy Astrophysical Phenomena · Physics 2026-01-26 Braden J. Marazzo-Nowicki , Paul Tiede , Dominic O. Chang , Daniel C. M. Palumbo , Michael D. Johnson

In a recent work [arXiv:2307.13489 [gr-qc]], we have described spherically symmetric and static quantum black holes as deformations of the classical Schwarzschild metric that depend on the physical distance to the horizon. We have developed…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Manuel Del Piano , Stefan Hohenegger , Francesco Sannino

We investigate the astrophysical consequences of black holes in quadratic gravity, characterized by the parameters $S_0$, $S_2$, $m_0$ and $m_2$, in addition to the black hole mass $M$. To evaluate the physical validity of the fundamental…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Somi Aktar , Niyaz Uddin Molla , Farook Rahaman , G. Mustafa

Under very general assumptions on the accretion flow geometry, images of a black hole illuminated by electromagnetic radiation display a sequence of photon rings (demagnified and rotated copies of the direct image) which asymptotically…

General Relativity and Quantum Cosmology · Physics 2024-07-24 Maciek Wielgus

This work is devoted to investigate some consequences of black holes physics beyond the domain of general relativity, mainly in effective extra dimensional models. The investigation is carried along three gravitational effects, namely the…

General Relativity and Quantum Cosmology · Physics 2019-02-28 Rogerio Teixeira Cavalcanti

The coalescence of massive black holes generates gravitational waves (GWs) that will be measurable by space-based detectors such as LISA to large redshifts. The spins of a binary's black holes have an important impact on its waveform.…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Ryan N. Lang , Scott A. Hughes

In this work we derive novel analytical expressions for the mass and distance of a Schwarzschild black hole (BH), as well as for the orbital radius of test particles orbiting it, it terms of astrophysical observables measured throughout the…

General Relativity and Quantum Cosmology · Physics 2026-05-12 J. R. Fernández-Moreno , A. González-Juárez , A. Herrera-Aguilar

The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark…

High Energy Physics - Phenomenology · Physics 2025-09-22 Yifan Chen , Ran Ding , Yuxin Liu , Yosuke Mizuno , Jing Shu , Haiyue Yu , Yanjie Zeng

In this work, gravitational lensing in the weak and strong field limits is investigated for black hole spacetime within the framework of Hu-Sawicki $f(R)$ gravity. We employ the Ishihara et al. approach for weak lensing and adopt Bozza's…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Gayatri Mohan , Nashiba Parbin , Umananda Dev Goswami