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Related papers: On M87$^*$ and SgrA$^*$ Observational Constraints …

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Motivated by recent Event Horizon Telescope findings, we investigate constrained optics of rotating black holes in Einstein-Maxwell-scalar gravity theory. Precisely, we mainly study the parameter effects on two relevant optical concepts…

High Energy Physics - Theory · Physics 2024-11-19 Hajar Belmahi

We study the black hole's shadow for Schwarzschild - de Sitter and Kerr - de Sitter metrics with the contribution of the cosmological constant \Lambda. Based on the reported parameters of the M87* black hole shadow we obtain constraints for…

General Relativity and Quantum Cosmology · Physics 2021-01-29 A. Stepanian , Sh. Khlghatyan , V. G. Gurzadyan

Recently, the \textit{EHT} collaboration unveiled the shadow images of the supermassive black hole (SMBH) M87* and Sgr A*, with angular radii of $42\pm3$\,$\mu$as and $48.7\pm7.0$\,$\mu$as, respectively. These observations are consistent…

High Energy Astrophysical Phenomena · Physics 2025-10-07 Yuan Tan , Youjun Lu , Kunyu Song

In this paper, we use a suitable conformal rescaling to construct static and rotating regular black holes in conformal massive gravity. The new metric is characterized by the mass $M$, the "scalar charge" $Q$, the angular momentum parameter…

General Relativity and Quantum Cosmology · Physics 2020-02-18 Kimet Jusufi , Mubasher Jamil , Hrishikesh Chakrabarty , Qiang Wu , Cosimo Bambi , Anzhong Wang

Recent observational data from the Event Horizon Telescope (EHT) collaboration provide convincing realistic evidence for the existence of black hole rotation. From a phenomenological perspective, a recently proposed stable rotating regular…

General Relativity and Quantum Cosmology · Physics 2025-01-15 Chen-Hao Xie , Yu Zhang , Qi Sun , Qi-Quan Li , Peng-Fei Duan

In this paper, we report on exact charged black hole solutions in symmergent gravity with Maxwell field. Symmergent gravity induces the gravitational constant $G$, quadratic curvature coefficient $c_{\rm O}$, and the vacuum energy $V_{\rm…

General Relativity and Quantum Cosmology · Physics 2023-09-12 Beyhan Puliçe , Reggie C. Pantig , Ali Övgün , Durmuş Demir

With the help of CUDA high-performance numerical codes exploited in machine learning, we investigate the shadow aspect of new rotating and charged black holes using the Dunkl derivative formalism. Precisely, we first establish the…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Saad Eddine Baddis , Adil Belhaj , Hajar Belmahi , Maryem Jemri

We study the strong gravitational lensing effect around rotating black holes in different gravity theories. By calculating the deflection angle of strong gravitational lensing, we evaluate the lensing observables including the image…

General Relativity and Quantum Cosmology · Physics 2022-09-20 Xiao-Mei Kuang , Zi-Yu Tang , Bin Wang , Anzhong Wang

In this paper, we investigate the strong gravitational lensing effects and optical appearances around a spherically symmetric regular black hole, whose metric is derived from a non-singular collapsing dust ball model in asymptotically safe…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Xiao-Jun Gao

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

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

In this work, we have studied weak gravitational lensing effect around black hole and determine shadow radius in GUP-corrected-Schwarzschild spacetime (S-GUP) in presence of plasma environment. We started with orbits of photons around black…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Husanboy Hoshimov , Odil Yunusov , Farruh Atamurotov , Mubasher Jamil , Ahmadjon Abdujabbarov

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

We study the effects of emission geometry on the capability to constrain black hole parameters from measurements of the shadow and inner-shadow of a Reissner-Nordstr\"om black hole. We investigate the capability to constrain mass, charge,…

High Energy Astrophysical Phenomena · Physics 2026-02-17 Julien A. Kearns , Dominic O. Chang , Daniel C. M. Palumbo , Shane W. Davis

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

We consider a black hole mimicker given by an exact solution of the stationary and axially symmetric field equations in vacuum known as the $\delta$-Kerr metric. We study its optical properties based on a ray-tracing code for photon motion…

General Relativity and Quantum Cosmology · Physics 2022-07-25 Song Li , Temurbek Mirzaev , Ahmadjon A. Abdujabbarov , Daniele Malafarina , Bobomurat Ahmedov , Wen-Biao Han

We investigate the strong gravitational lensing phenomena caused by a black hole with a dark matter halo. In this study, we examine strong gravitational lensing with two significant dark matter models: the universal rotation curve model and…

General Relativity and Quantum Cosmology · Physics 2023-11-03 Niyaz Uddin Molla , Himanshu Chaudhary , Dhruv Arora , Farruh Atamurotov , Ujjal Debnath , G. Mustafa

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

This article deals with the study of some properties of the static and rotating black holes in Kalb-Ramond gravity in four dimensional spacetime. First, we discuss the action of the corresponding theory and the static black hole metric.…

General Relativity and Quantum Cosmology · Physics 2023-10-20 M. Zubair , Muhammad Ali Raza , Eiman Maqsood

We discuss the horizon properties, shadow cast, and the weak gravitational lensing of charged rotating regular black holes, which in addition to mass ($M$) and rotation parameter ($a$) have an electric charge ($Q$) and magnetic charge…

General Relativity and Quantum Cosmology · Physics 2019-12-12 Rahul Kumar , Sushant G. Ghosh , Anzhong Wang
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