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Related papers: Distinguishing rotating Kiselev black hole from na…

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We study a Kerr-like black hole and naked singularity in perfect fluid dark matter (PFDM). The critical value of spin parameter $a_c$ is presented to differentiate the black hole from naked singularity. It is seen that for any fixed value…

General Relativity and Quantum Cosmology · Physics 2019-02-01 Muhammad Rizwan , Mubasher Jamil , Kimet Jusufi

We study the spin precession of a test gyroscope attached to a stationary observer in Kerr-Newman spacetime to distinguish a naked singularity from a black hole. Extending earlier work on Kerr, we examine how the electric charge \(Q\)…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Arindam Kumar Chatterjee , Parthapratim Pradhan

We propose here a specific criterion to address the existence or otherwise of Kerr naked singularities, in terms of the precession of the spin of a test gyroscope due to the frame dragging by the central spinning body. We show that there is…

General Relativity and Quantum Cosmology · Physics 2017-02-08 Chandrachur Chakraborty , Prashant Kocherlakota , Pankaj S. Joshi

We study here the precession of the spin of a test gyroscope attached to a stationary observer in the Kerr spacetime, specifically, to distinguish naked singularity (NS) from black hole (BH). It was shown recently that for gyros attached to…

General Relativity and Quantum Cosmology · Physics 2017-04-14 Chandrachur Chakraborty , Prashant Kocherlakota , Mandar Patil , Sudip Bhattacharyya , Pankaj S. Joshi , Andrzej Królak

Various studies show that the gravitational collapse of inhomogeneous matter clouds leads to naked singularity formation. We investigate here the spin precession frequency of a test gyroscope attached to a stationary observer in a rotating…

General Relativity and Quantum Cosmology · Physics 2025-05-19 Tehreem Zahra , Mubasher Jamil , Mustapha Azreg-Aïnou

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…

General Relativity and Quantum Cosmology · Physics 2025-01-22 Parthapratim Pradhan

We examine the geometrical differences between the black hole~(BH) and naked singularity~(NS) or superspinar via Lense-Thirring~(LT) precession in spinning modified-gravity~(MOG). For BH case, we show that the LT precession…

General Relativity and Quantum Cosmology · Physics 2024-08-27 Parthapratim Pradhan

In this paper, we study the spin precession frequency of a test gyroscope attached to a stationary observer in the five dimensional rotating Kaluza-Klein black hole (RKKBH). We derive the conditions under which the test gyroscope moves…

General Relativity and Quantum Cosmology · Physics 2020-03-19 Mustapha Azreg-Aïnou , Mubasher Jamil , Kai Lin

We investigate the gravitational lensing scenario due to Schwarzschild-like black hole surrounded by quintessence (Kiselev black hole). We work for the special case of Kiselev black hole where we take the state parameter…

General Relativity and Quantum Cosmology · Physics 2015-10-21 Azka Younas , Mubasher Jamil , Sebastian Bahamonde , Saqib Hussain

In this paper, we investigate the properties of the Lense-Thirring precession frequency and periastron precession of the relativistic bound orbits in slowly rotating naked singularity spacetimes. We show that the precession frequencies of a…

General Relativity and Quantum Cosmology · Physics 2021-09-24 Parth Bambhaniya , Jay S. Verma , Dipanjan Dey , Pankaj S. Joshi , Ashok B. Joshi

Quintessential dark energy with density $\rho$ and pressure $p$ is governed by an equation of state of the form $p=-\omega_{q}\rho$ with the quintessential parameter $\omega_q\in(-1;-1/3)$. We derive the geometry of quintessential rotating…

General Relativity and Quantum Cosmology · Physics 2015-12-07 Bobir Toshmatov , Zdeněk Stuchlík , Bobomurat Ahmedov

Can a naked singularity (NkS) be distinguished from a black hole (BH)? We have investigated it with cutting-edge general relativistic magneto-hydrodynamic (GRMHD) simulations, followed by general relativistic radiation transfer (GRRT)…

High Energy Astrophysical Phenomena · Physics 2024-10-21 Indu K. Dihingia , Akhil Uniyal , Yosuke Mizuno

We investigate the frame-dragging effect of the hairy Kerr spacetimes on the spin of a test gyro and accretion disk. Firstly, we analyze Lense-Thirring (LT) precession frequency, geodetic precession frequency, and the general spin…

General Relativity and Quantum Cosmology · Physics 2023-06-21 Meng-He Wu , Hong Guo , Xiao-Mei Kuang

We study null and timelike constant radii geodesics in the environment of an over-spinning putative Kerr-type naked singularity. We are particularly interested in two topics: first, the differences of the shadows of the naked rotating…

General Relativity and Quantum Cosmology · Physics 2024-02-20 Aydin Tavlayan , Bayram Tekin

Naked singularities are hypothetical astrophysical objects, characterized by a gravitational singularity without an event horizon. Penrose has proposed a conjecture, according to which there exists a cosmic censor who forbids the occurrence…

General Relativity and Quantum Cosmology · Physics 2011-01-17 Z. Kovacs , T. Harko

In this work, we investigate the thermodynamic properties, Hawking-radiation sparsity, and greybody-factor bounds of a hairy Kiselev black hole surrounded by a quintessential fluid. The spacetime geometry contains, in addition to the…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Faizuddin Ahmed , Fernando M. Belchior , Allan R. P. Moreira , Abdelmalek Bouzenada

We present a systematic analysis of the complete set of observations of the black hole (BH) binary XTE J1550-564 obtained by the Rossi X-ray Timing Explorer. We study the fast time variability properties of the source and determine the spin…

High Energy Astrophysical Phenomena · Physics 2015-06-18 S. E. Motta , T. Muñoz-Darias , A. Sanna , R. Fender , T. Belloni , L. Stella

We investigate quasi-periodic oscillations (QPOs) as a diagnostic tool for probing frame-dragging effects and accretion disk physics in the spacetime of a rotating regular magnetic black hole (BH). Specifically, we analyze the precession of…

General Relativity and Quantum Cosmology · Physics 2026-02-13 R. H. Ali , Meng-He Wu , Hong Guo , Xiao-Mei Kuang

We present a detailed study of higher-order photon rings of an accreting Kerr naked singularity (KNS) with dimensionless spin parameter $a=1.01$; i.e., a horizonless, overly spinning compact object. Motivated by horizon-scale…

High Energy Astrophysical Phenomena · Physics 2025-11-27 Hina Suzuki , Yosuke Mizuno , Akhil Uniyal , Indu Kalpa Dihingia , Tintin Nguyen , Chi-kwan Chan

As a local effect of dynamical dark energy, bending of light in the presence of a spherically symmetric and static black hole surrounded by quintessence has been studied. Having in mind recent observational data, we have treated the problem…

General Relativity and Quantum Cosmology · Physics 2019-11-25 R. Saadati , F. Shojai
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