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Related papers: Circular geodesics in Kerr-Newman-Kasuya black hol…

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In this paper, we investigate the gravitational lensing properties of magnetically charged black holes within the framework of nonlinear electrodynamics. We derive the deflection angle and examine the influence of the nonlinear…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Hira Waseem , Nikko John Leo S. Lobos , Ali Övgün , Reggie C. Pantig

This paper systematically revisits the critical orbits of test particles moving in various black hole backgrounds, including the Schwarzschild, Reissner-Nordstr\"{o}m, Kerr, and Kerr-Newman spacetimes. We identify the critical orbit cases…

General Relativity and Quantum Cosmology · Physics 2026-02-11 Ping Li , Jun Cheng , Jiang-he Yang

We study the shadow cast or silhouette generated by a Kerr-Newman-Kasuya (KNK) spacetime (rotating dyon black hole). It is shown that in addition to the angular momentum of the black hole, the dyon charge also affects the shadow image of…

General Relativity and Quantum Cosmology · Physics 2018-10-23 Ali Övgün , İzzet Sakallı , Joel Saavedra

We present dynamical properties of linear waves and null geodesics valid for Kerr and Kerr-de Sitter black holes and their stationary perturbations. The two are intimately linked by the geometric optics approximation. For the nullgeodesic…

General Relativity and Quantum Cosmology · Physics 2013-10-28 Semyon Dyatlov , Maciej Zworski

By using the Newman-Penrose formalism and 't Hooft brick-wall model, the quantum entropies of the Kerr-Newman black hole due to the Dirac and electromagnetic fields are calculated and the effects of the spins of the photons and Dirac…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jiliang Jing , Mu-Lin Yan

We study circular geodesic motion of test particles and photons in the Bardeen and Ayon-Beato-Garcia (ABG) geometry describing spherically symmetric regular black-hole or no-horizon spacetimes. While the Bardeen geometry is not exact…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Zdenek Stuchlik , Jan Schee

Maxwell's equations are invariant under both duality rotations and conformal transformations. Recently Bandos, Lechner, Sorokin, and Townsend have found a nonlinear generalisation of electrodynamics which possesses both of these symmetries.…

General Relativity and Quantum Cosmology · Physics 2020-12-14 Daniel Flores-Alfonso , Blanca Angélica González-Morales , Román Linares , Marco Maceda

"Almost all" seems to be known about isolated stationary black holes in asymptotically flat space-times and about the behaviour of {\em test} matter and fields in their backgrounds. The black holes likely present in galactic nuclei and in…

General Relativity and Quantum Cosmology · Physics 2021-04-07 Oldřich Semerák , Petra Suková

We study here circular timelike geodesics in the Janis-Newman-Winicour and Gamma metric spacetimes which contain a strong curvature naked singularity and reduce to the Schwarzschild metric for a specific value of one of the parameters. We…

General Relativity and Quantum Cosmology · Physics 2012-06-20 Anirban N. Chowdhury , Mandar Patil , Daniele Malafarina , Pankaj S. Joshi

The circular motion of charged test particles in the gravitational field of a Reissner-Nordstr\"{o}m black hole in Anti de Sitter space-time is investigated, using a set of independent parameters, such as charge Q, mass M and cosmological…

High Energy Physics - Theory · Physics 2019-03-12 Chandrasekhar Bhamidipati , Shrohan Mohapatra

Gravitational-wave astronomy can give us access to the structure of black holes, potentially probing microscopic or even Planckian corrections at the horizon scale, as those predicted by some quantum-gravity models of exotic compact…

General Relativity and Quantum Cosmology · Physics 2017-12-07 Elisa Maggio , Paolo Pani , Valeria Ferrari

A three-dimensional light-like foliation of a spacetime geometry is one particular way of studying its light cone structure and has important applications in numerical relativity. In this paper, we execute such a foliation for the…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Michael T. N. Imseis , Abdulrahim Al Balushi , Robert B. Mann

We investigate the motions of charged particles in the near horizon region of an extreme Kerr black hole with weak electromagnetic fields. There is an enhanced symmetry in the NHEK geometry. We find that when the electromagnetic field…

General Relativity and Quantum Cosmology · Physics 2023-06-13 Yehui Hou , Zhenyu Zhang , Minyong Guo , Bin Chen

A new feature of the rotating black holes is the existence in their ergosphere of trajectories of particles with negative and zero energies. Here we analyze general properties of such trajectories comparing them with usual trajectories of…

General Relativity and Quantum Cosmology · Physics 2016-11-01 A. A. Grib , Yu. V. Pavlov

We present an elementary evaluation of the surface areas of the event horizon and stationary limit surface for an uncharged Kerr black hole. The latter appears not to have been previously given in the literature, and permits us to suggest…

General Relativity and Quantum Cosmology · Physics 2009-10-31 C. A. Pickett , J. D. Zund

Source-free equations of nonlinear electrodynamics minimally coupled to gravity (NED-GR) admit regular axially symmetric asymptotically Kerr-Newman solutions, which describe electrically charged rotating black holes and spinning solitons.…

General Relativity and Quantum Cosmology · Physics 2015-10-07 Irina Dymnikova

The existence of quintessential dark energy around a black hole has considerable consequences on its spacetime geometry. Hence, in this article, we explore its effect on horizons and the silhouette generated by a Kerr-Newman black hole in…

General Relativity and Quantum Cosmology · Physics 2020-06-23 Saeed Ullah Khan , Jingli Ren

This work investigates the optical properties of a static, spherically symmetric, electrically charged black hole in f(R) gravity coupled to Euler-Heisenberg(EH) nonlinear electrodynamics(NLED). By analyzing photon trajectories in this…

General Relativity and Quantum Cosmology · Physics 2026-01-16 Khadije Jafarzade , Saira Yasmin , Mubasher Jamil

We consider the stationary metrics that have both the black hole and the ergoregion. The class of such metric contains, in particular, the Kerr metric. We study the Cauchy problem with highly oscillatory initial data supported in a…

Mathematical Physics · Physics 2016-11-21 Gregory Eskin

In this analysis, we investigate the polarization radiation imaging of Kerr-Newman black holes, with a particular focus on the impact of black hole charge on photon propagation and polarization characteristics. By extending the traditional…

General Relativity and Quantum Cosmology · Physics 2026-04-10 Xin Li , Sen Guo , Pei Wang , En-Wei Liang , Huan Deng , Yu Liang , Xiao-Xiong Zeng , Kai Lin , Qing-Quan Jiang