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Related papers: Shadows of naked singularity in Brans-Dicke gravit…

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In this paper we study gravitational lensing in the strong field limit from the perspective of cosmic censorship, to investigate whether or not naked singularities, if at all they exist in nature, can be distinguished from black holes. We…

General Relativity and Quantum Cosmology · Physics 2012-09-21 Satyabrata Sahu , Mandar Patil , D. Narasimha , Pankaj S. Joshi

A beyond Horndeski theory is considered that admits wormholes, black holes and naked singularities. In this theory the shadow images of the black holes and the exotic compact objects (ECOs), illuminated by an optically and geometrically…

General Relativity and Quantum Cosmology · Physics 2024-01-30 Hyat Huang , Jutta Kunz , Deeshani Mitra

In this paper, we derive the solutions of orbit equations for a class of naked singularity spacetimes, and compare these with timelike orbits, that is, particle trajectories in the Schwarzschild black hole spacetime. The Schwarzschild and…

General Relativity and Quantum Cosmology · Physics 2019-12-11 Parth Bambhaniya , Ashok B. Joshi , Dipanjan Dey , Pankaj S. Joshi

Direct imaging of supermassive black holes (SMBHs) at event horizon scale resolutions, as recently done by the Event Horizon Telescope, allows for testing alternative models to SMBHs such as Kerr naked singularities (KNSs). We demonstrate…

High Energy Astrophysical Phenomena · Physics 2023-08-28 Bao Nguyen , Pierre Christian , Chi-kwan Chan

An exact four-dimensional black hole solution of gravity with a minimally coupled self-interacting scalar field is reported. The event horizon is a surface of negative constant curvature enclosing the curvature singularity at the origin,…

High Energy Physics - Theory · Physics 2009-11-10 Cristian Martinez , Ricardo Troncoso , Jorge Zanelli

Static, spherically symmetric configurations of gravity with nonminimally coupled scalar fields are considered in D-dimensional space-times in the framework of generalized scalar-tensor theories. We seek special cases when the system has no…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kirill A. Bronnikov

We study black holes in the recently proposed ghost-free theory with two gravitons, one of which is massive and another is massless. These black holes possess a regular event horizon which is common for both metrics and has the same values…

High Energy Physics - Theory · Physics 2013-05-30 Mikhail S. Volkov

It is now known that the shadow is not only the property of a black hole, it can also be cast by other compact objects like naked singularities. However, there exist some novel features of the shadow of the naked singularities which are…

General Relativity and Quantum Cosmology · Physics 2021-04-14 Parth Bambhaniya , Dipanjan Dey , Ashok B. Joshi , Pankaj S. Joshi , Divyesh N. Solanki , Aadarsh Mehta

Regular black hole is one of the bottom-up solutions designed to eliminate the singularity at the center of black holes. Its horizonless solution has gained interest recently to model ultracompact star. Despite interesting, this proposal is…

General Relativity and Quantum Cosmology · Physics 2024-11-26 M. F. Fauzi , H. S. Ramadhan , A. Sulaksono

It has recently been argued that non-trivial Brans-Dicke black hole solutions different from the usual Schwarzschild solution could exist. We attemt here to ``censor'' these non-trivial Brans-Dicke black hole solutions by examining their…

General Relativity and Quantum Cosmology · Physics 2011-04-20 Hongsu Kim

We study Einstein gravity minimally coupled to a scalar field in a static, spherically symmetric space-time in four dimensions. Black hole solutions are shown to exist for a phantom scalar field whose kinetic energy is negative. These…

General Relativity and Quantum Cosmology · Physics 2008-11-26 K. A. Bronnikov , M. S. Chernakova , J. C. Fabris , N. Pinto-Neto , M. E. Rodrigues

We revisit static, spherically symmetric solutions to AdS-Einstein gravity with a conformally coupled scalar field (and no self-interaction potential) in four dimensions. We first observe that a convenient choice of coordinates leads to a…

General Relativity and Quantum Cosmology · Physics 2024-09-10 Marcello Ortaggio

We obtained new hairy black hole solutions in Einstein-scalar theory, including asymptotic flat, de Sitter and anti-de Sitter black holes. The theory is inspired by Ref. [1], where traversable wormhole solutions from an Einstein-phantom…

General Relativity and Quantum Cosmology · Physics 2024-03-19 Xiao-Ping Rao , Hyat Huang , Jinbo Yang

We study bound orbits near the centres of static, spherically symmetric, asymptotically flat configurations of a self-gravitating scalar field minimally coupled to gravity. In our approach, a nonlinear scalar field is considered as an…

General Relativity and Quantum Cosmology · Physics 2019-08-29 I. M. Potashov , Ju. V. Tchemarina , A. N. Tsirulev

We study the quintessential properties of the Black Hole solutions in a scalar--tensor theory of gravity with Higgs potential in view of the static and spherically symmetric line element. In view of our earlier results,…

General Relativity and Quantum Cosmology · Physics 2010-11-29 Hemwati Nandan , Nils M. Bezares-Roder , Heinz Dehnen

Black holes are thought to describe the geometry of massive, dark compact objects in the universe. To further support and quantify this long-held belief requires knowledge of possible, if exotic alternatives. Here, we wish to understand how…

General Relativity and Quantum Cosmology · Physics 2022-02-02 Vitor Cardoso , Caio F. B. Macedo , Kei-ichi Maeda , Hirotada Okawa

Spontaneous scalarization in Einstein-scalar-Gauss-Bonnet theory admits both vacuum-general relativity (GR) and scalarized hairy black holes as valid solutions, which provides a distinctive signature of new physics in strong gravity regime.…

General Relativity and Quantum Cosmology · Physics 2024-12-05 Xi-Jing Wang , Yuan Meng , Xiao-Mei Kuang , Kai Liao

The first images of black hole shadows open new possibilities to constrain modern extended gravity theories. We present the method of shadow background calculation for black hole solutions in the form of Taylor series where $g_{11} = -…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. Prokopov , S. Alexeyev , O. Zenin

In the present study we search for a new class of wormhole solutions in the framework of Brans-Dicke (BD) theory in the presence of anisotropic matter distribution. Considering a linear equation of state (EoS) between radial pressure and…

General Relativity and Quantum Cosmology · Physics 2025-09-16 Amir Hadi Ziaie , Naser Sadeghnezhad , Akbar Jahan

We investigate three-dimensional black hole solutions in the realm of pure and new massive gravity in 2+1 dimensions induced on a 2-brane embedded in a flat four-dimensional spacetime. There is no cosmological constant neither on the brane…

High Energy Physics - Theory · Physics 2011-10-26 D. Bazeia , F. A. Brito , F. G. Costa