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Strong self-gravitational fields enable the realization of macroscopic odd-parity quantum objects. Using ray-tracing methods, we systematically analyze the dynamics of photons and the shadow features of rotating black holes with parity-odd…

General Relativity and Quantum Cosmology · Physics 2025-10-14 Yang Huang , Dao-Jun Liu , Hongsheng Zhang

We study the gravitational lensing effects of a static, asymptotically flat black hole with primary scalar hair in Beyond Horndeski gravity, focusing on the strong lensing regime. Recently, in Ref. [1], we placed constraints on the scalar…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Mohsen Fathi

What does a black hole look like? In 1+3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer's sky often called the black hole shadow, as supported by the EHT observations. In higher…

General Relativity and Quantum Cosmology · Physics 2024-10-10 João P. A. Novo , Pedro V. P. Cunha , Carlos A. R. Herdeiro

We address the astrophysical imaging of a family of deformed Kerr black holes (BHs). These are stationary, asymptotically flat black hole (BH) spacetimes, that are solutions of General Relativity minimally coupled to a massive, complex…

General Relativity and Quantum Cosmology · Physics 2016-11-02 F. H. Vincent , E. Gourgoulhon , C. Herdeiro , E. Radu

The shadow of a black hole serves as a pristine window into the strong-gravity regime, with cuspy feature emerging as a smoking-gun signature of physics beyond the Kerr paradigm. In this paper, we extend the work of [arXiv:2601.15612…

General Relativity and Quantum Cosmology · Physics 2026-04-07 Shao-Wen Wei , Yu-Xiao Liu

We examine observational signatures of the asymptotically de Sitter branch of static spherically symmetric Horndeski/Galileon solutions. Our analysis reveales that possible deviations of the photon sphere size from those of the GR…

General Relativity and Quantum Cosmology · Physics 2016-10-25 D. A. Tretyakova , T. M. Adyev

We consider spherically symmetric and static charged black holes in Einstein-Gauss-Bonnet-Maxwell gravities in general $D\ge 5$ dimensions and study their photon spheres and black hole shadows. We show that they all satisfy the sequence of…

General Relativity and Quantum Cosmology · Physics 2020-06-10 Liang Ma , H. Lu

A brief illustrative discussion of the shadows of black holes at local and cosmological distances is presented. Starting from definition of the term and discussion of recent observations, we then investigate shadows at large, cosmological…

General Relativity and Quantum Cosmology · Physics 2019-10-24 G. S. Bisnovatyi-Kogan , O. Yu. Tsupko , V. Perlick

The shadow of a rotating black hole with nonvanishing gravitomagnetic charge has been studied. It was shown that in addition to the angular momentum of black hole the gravitomagnetic charge term deforms the shape of the black hole shadow.…

This paper investigates the shadow of a charged rotating non-commutative black hole. For this purpose, we first formulate the null geodesics and study the effects of non-commutative charge on the photon orbit. We then explore the effect of…

General Relativity and Quantum Cosmology · Physics 2016-12-21 M. Sharif , Sehrish Iftikhar

We investigate the strong gravitational lensing and shadow properties of the black hole in the context of bumblebee gravity, characterized by a global monopole charge $\kappa\eta^2$ and a Lorentz symmetry breaking parameter $\gamma$. We…

General Relativity and Quantum Cosmology · Physics 2026-01-01 Bijendra Kumar Vishvakarma , Shubham Kala

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. The Einstein-Bel-Robinson gravity, with quartic curvature modification, motivated Sajadi et al to explore static spherically…

General Relativity and Quantum Cosmology · Physics 2024-04-11 B. Hamil , B. C. Lütfüoğlu

A certain type of matter with anisotropic pressures can add to the Reissner-Nordstr\"om metric a term proportional to a power of the radial coordinate. Using the standard method of separating variables for the Hamilton-Jacobi equation, we…

General Relativity and Quantum Cosmology · Physics 2023-01-30 Javier Badía , Ernesto F. Eiroa

When the the shadow image of a supermassive black hole in the center of M87 was obtained a new era in the observational astrophysics began. The resolution improvement would allow to test extended gravity models at event horizon scales. We…

General Relativity and Quantum Cosmology · Physics 2020-08-26 S. O. Alexeyev , V. A. Prokopov

We consider a spherically symmetric black hole metric in (3+1)-dimensions in presence of a positive cosmological constant $\Lambda$. We use a general approach as proposed in \cite{1} to transform the metric in co-moving coordinates. Then…

General Relativity and Quantum Cosmology · Physics 2022-12-12 Anish Das , Ashis Saha , Sunandan Gangopadhyay

In this paper, we explore the Kerr-Sen-Taub-NUT spacetime with the inclusion of the Manko-Ruiz parameter. We demonstrate the separability of the Hamilton-Jacobi equation for a classical test particle in this spacetime and, using the null…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Haryanto M. Siahaan

Within 5-10 years, very-long baseline interferometry (VLBI) facilities will be able to directly image the accretion flow around SgrA$^*$, the super-massive black hole candidate at the center of the Galaxy, and observe the black hole…

General Relativity and Quantum Cosmology · Physics 2014-06-19 Naoki Tsukamoto , Zilong Li , Cosimo Bambi

In this paper, we investigate the photon sphere, shadow radius and quasinormal modes of a four-dimensional charged Einstein-Gauss-Bonnet black hole. The perturbation of a massless scalar field in the black hole's background is adopted. The…

General Relativity and Quantum Cosmology · Physics 2021-09-01 Deyou Chen , Chuanhong Gao , Xianming Liu , Chengye Yu

One of the most important and actual issues in relativistic astrophysics is testing gravity theories and obtaining constraint values for the parameters of black holes using observational data. In this research, we aimed to explore the…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Saeed Ullah Khan , Javlon Rayimbaev , Furkat Sarikulov , Ozodbek Abdurakhmonov

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
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