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Related papers: Weak field deflection angle and analytical paramet…

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In this work, we observe that in the presence of the string cloud parameter $a$ and the quintessence parameter $\gamma$, with the equation of state parameter $\omega_q={-2}/{3}$ the radius of the shadow of the Schwarzschild black hole…

General Relativity and Quantum Cosmology · Physics 2022-12-01 Ghulam Mustafa , Farruh Atamurotov , Ibrar Hussain , Sanjar Shaymatov , Ali Övgün

Inspired by the two different dark matter frameworks that were studied recently: one that arises from the non-local effects of entanglement entropy as emergent gravity (characterized by the parameter $\xi(M)$, and zero-point scale length…

General Relativity and Quantum Cosmology · Physics 2024-06-11 Reggie C. Pantig

In this paper, we argue that one can calculate the weak deflection angle of light in the background of Einstein-Maxwell-Dilaton-Axion black hole using the Gauss-Bonnet theorem. To support this, the optical geometry of the black hole with…

General Relativity and Quantum Cosmology · Physics 2019-11-19 W. Javed , R. Babar , A. Övgün

This article investigates the geodesic structure and deflection angle of charged black holes in the presence of a nonzero vacuum expectation value background of the Kalb-Ramond field. Topics explored include null and timelike geodesics,…

General Relativity and Quantum Cosmology · Physics 2024-08-20 Ahmad al-Badawi , Sanjar Shaymatov , Izzet Sakallı

In this letter, we have investigated the deflection angle of light by wormholes using a new geometrical method known as Gibbons-Werner method (GW). In particular we have calculated the deflection angle of light in the weak limit…

General Relativity and Quantum Cosmology · Physics 2017-08-22 Kimet Jusufi

Recent observations of the supermassive black holes $ M87^{*} $ and Sgr A$^{*}$ by the Event Horizon Telescope (EHT) have sparked intensified interest in studying the optical appearance of black holes (BHs). Inspired by this, we carry out a…

General Relativity and Quantum Cosmology · Physics 2025-08-14 Khadije Jafarzade , Zeynab Bazyar , Sara Saghafi , Kourosh Nozari

The bending angle of light is a central quantity in the theory of gravitational lensing. We develop an analytical perturbation framework for calculating the bending angle of light rays lensed by a Schwarzschild black hole. Using a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Savitri V. Iyer , Arlie O. Petters

The M87* black hole shadow observation by the Event Horizon Telescope (EHT) has enabled us to test the modified gravity theories in the extreme-field regime and estimating the black hole parameters. Having this assertion, we investigate the…

General Relativity and Quantum Cosmology · Physics 2023-02-06 Sushant G. Ghosh , Rahul Kumar Walia

We consider \s black hole (BH) embedded in a Dehnen-$(1,4,0)$ type dark matter halo (DDM) with two additional parameters - core radius $r_s$ and core density $\rs$ apart from mass $M$. We analyze the event horizon, photon orbits, and ISCO…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Sohan Kumar Jha

We study gravitational lensing by a Reissner-Nordstrom (RN) black hole in the weak field limit. We obtain the basic equations for the deflection angle and time delay and find analytical expressions for the positions and amplifications of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 M. Sereno

In this paper, we study the deflection of light by a class of phantom black hole and wormhole solutions in the weak limit approximation. More specifically, in the first part of this work, we study the deflection of light by…

General Relativity and Quantum Cosmology · Physics 2019-05-01 Ali Övgün , Galin Gyulchev , Kimet Jusufi

We investigate the thermodynamic properties of charged anti-de Sitter black holes surrounded by a cloud of strings in bumblebee gravity. In this framework, the cloud-of-strings parameter $\alpha$ and the Lorentz-violating parameter $\ell$…

General Relativity and Quantum Cosmology · Physics 2026-03-20 Faizuddin Ahmed , Edilberto O. Silva

In this study, we have considered the Kerr-like black hole (BH) model in Horndeski gravity and analyse the visual characteristics of shadow images under two illumination models, such as a celestial light source and a thin accretion disk. To…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Xiao-Xiong Zeng , Chen-Yu Yang , M. Israr Aslam , Rabia Saleem

The nature of black holes (BHs) and their potential deviations from classical General Relativity (GR) remain central questions in modern astrophysics. Nonlinear electrodynamics (NED) offers a promising mechanism to construct regular BHs…

General Relativity and Quantum Cosmology · Physics 2025-12-19 Javokhir Sharipov , Mirzabek Alloqulov , Pankaj Sheoran , Sanjar Shaymatov

In this study, we explore a static, spherically symmetric black hole solution in the context of a self-interacting Kalb-Ramond field coupled with a global monopole. By incorporating the effects of Lorentz-violating term $\ell$ and the…

General Relativity and Quantum Cosmology · Physics 2025-04-10 Mohsen Fathi , Ali Övgün

In this work, we investigate the optical properties of a new black hole recently obtained from the Dunkl operator formalism involving a relevant parameter denoted by $\xi$. Concretely, we first investigate the shadows, the Lyapunov…

General Relativity and Quantum Cosmology · Physics 2024-12-13 N. Askour , A. Belhaj , L. Chakhchi , H. El Moumni , K. Masmar

Nonlinear electrodynamic (NLED) theories are well-motivated for their extensions to classical electrodynamics in the strong field regime, and have been extensively investigated in seeking for regular black hole solutions. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2021-07-21 Qi-Ming Fu , Li Zhao , Yu-Xiao Liu

The gravitational deflection of light is a critical test of modified theories of gravity. A few years ago, Gibbons and Werner introduced a definition of the deflection angle based on the Gauss-Bonnet theorem. In more recent years, Arakida…

General Relativity and Quantum Cosmology · Physics 2023-12-12 Flavio C. Sánchez , Armando A. Roque , Benito Rodríguez , Javier Chagoya

With an intent to examine the combined effect of non-linear electrodynamics (NED) and dark matter (DM), we obtain a static and spherically symmetric solution with the black hole (BH) magnetically charged and immersed in the Hernquist DM…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Sohan Kumar Jha

We analytically investigate the shadows cast by rotating black holes in the asymptotically safe gravity (ASG) by deriving complete null geodesics and observables using the Hamilton-Jacobi equation and Carter separable method. It turns out…

General Relativity and Quantum Cosmology · Physics 2020-07-13 Rahul Kumar , Balendra Pratap Singh , Sushant G. Ghosh