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Related papers: Bound orbits near scalar field naked singularities

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In the present work, we adopt a nonlinear scalar field theory coupled to the gravity sector to model galactic dark matter. We found analytical solutions for the scalar field coupled to gravity in the Newtonian limit, assuming an isotropic…

General Relativity and Quantum Cosmology · Physics 2021-05-19 R. A. C. Correa , P. H. R. S. Moraes , A. de Souza Dutra , O. L. Dors , W. de Paula , T. Frederico

The properties of static, spherically symmetric configurations are considered in the framework of two models of nonlocally corrected gravity, suggested in S. Deser and R. Woodard., Phys. Rev. Lett. 663, 111301 (2007), and S. Capozziello et…

High Energy Physics - Theory · Physics 2010-04-06 K. A. Bronnikov , E. Elizalde

We study strong gravitational lensing in a static, spherically symmetric, naked singularity spacetime, without a photon sphere. The nature of the singularity is found to be lightlike. We discuss the characteristic lensing features of this…

General Relativity and Quantum Cosmology · Physics 2020-09-25 Suvankar Paul

We study the collapse of a massless scalar field coupled to gravity. A class of blackhole solutions are identified. We also report on a class of solutions where collapse starts from a regular spacelike surface but then the collapsing scalar…

General Relativity and Quantum Cosmology · Physics 2011-07-22 Swastik Bhattacharya

We investigate the observational features of exact vacuum solutions in Brans-Dicke (BD) gravity, focusing on their implications for black hole shadow imaging. Motivated by the Event Horizon Telescope (EHT) observations, we revisit a class…

General Relativity and Quantum Cosmology · Physics 2025-09-17 Prajwal Hassan Puttasiddappa , Davi C Rodrigues , David F Mota

Motivated by the recently found 4-dimensional omega-deformed gauge supergravity, we investigate the black hole solutions within all the single scalar field consistent truncations of this theory. We construct black hole solutions that have…

High Energy Physics - Theory · Physics 2015-06-18 Andres Anabalon , Dumitru Astefanesei

Classical scalar fields have been proposed as possible candidates for the dark matter component of the universe. Given the fact that super-massive black holes seem to exist at the center of most galaxies, in order to be a viable candidate…

General Relativity and Quantum Cosmology · Physics 2012-08-01 Juan Barranco , Argelia Bernal , Juan Carlos Degollado , Alberto Diez-Tejedor , Miguel Megevand , Miguel Alcubierre , Darío Núñez , Olivier Sarbach

We explore circular geodesics of neutral test particles in the gravitational field of a rotating deformed mass. The geometry around this source is described by the Quevedo-Mashhoon solution, which corresponds to a naked singularity. To this…

The properties of universes are explored that are entirely in the interior of black holes in another universe, a `mother universe'. It is argued that these models offer a paradigm that may shed a new light on old cosmological problems. The…

General Relativity and Quantum Cosmology · Physics 2022-10-17 Herwig Dejonghe

We study effects of the particles coupling with scalar field (SF) on the distribution of stable circular orbits (SCO) around the naked singularity described by the well-known Fisher-Janis-Newman-Winicour solution. The power-law and…

General Relativity and Quantum Cosmology · Physics 2023-12-20 O. S. Stashko , V. I. Zhdanov

We study linear perturbations against static spherically symmetric background configurations of General Relativity with a real scalar field (SF), which is minimally coupled with gravity; it is non-linear due to the presence of the…

General Relativity and Quantum Cosmology · Physics 2023-12-19 O. S. Stashko , O. V. Savchuk , V. I. Zhdanov

In this paper, we investigate the light trajectories and shadow properties in the rotating version of null naked singularity (NNS) spacetime which is derived using the Newman- Janis algorithm without complexification method. We discuss some…

General Relativity and Quantum Cosmology · Physics 2022-09-21 Vishva Patel , Divya Tahelyani , Ashok B. Joshi , Dipanjan Dey , Pankaj S. Joshi

We introduce a two-parameter static, nonspherically-symmetric black hole solution in the Einstein theory of gravity coupled with a massless scalar field. The scalar field depends only on the polar coordinate $\theta$ in the spherical…

General Relativity and Quantum Cosmology · Physics 2025-02-21 S. Habib Mazharimousavi

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

We consider scalar dark matter models where the theory has a shift symmetry only broken by the scalar mass term. We restrict ourselves to K-essence kinetic terms where the shift symmetric part of the Lagrangian is a function of the first…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-11 Philippe Brax , Jose A. R. Cembranos , Patrick Valageas

We construct asymptotically flat, spinning, regular on and outside an event horizon, scalarised black holes (SBHs) in extended scalar-tensor-Gauss-Bonnet models. They reduce to Kerr BHs when the scalar field vanishes. For an illustrative…

General Relativity and Quantum Cosmology · Physics 2019-07-10 Pedro V. P. Cunha , Carlos A. R. Herdeiro , Eugen Radu

By utilizing non-standard slicings of 5-dimensional Schwarzschild and Schwarzschild-AdS manifolds based on isotropic coordinates, we generate static and spherically symmetric braneworld spacetimes containing shell-like naked null…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Sanjeev S. Seahra

We report on a numerical study of the spherically symmetric collapse of a self-gravitating massless scalar field. Earlier results of Choptuik(1992, 1994) are confirmed. The field either disperses to infinity or collapses to a black hole,…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Rufus S. Hamade , John M. Stewart

We study spherical charged black holes in the presence of a cosmological constant with corrections motivated by the theory of loop quantum gravity. The effective theory is constructed at the Hamiltonian level by introducing certain…

General Relativity and Quantum Cosmology · Physics 2023-04-12 Asier Alonso-Bardaji , David Brizuela , Raül Vera

The study investigates orbital motion of test particles near compact objects described by solutions involving massless scalar fields, electromagnetic fields, and nonlinear electrodynamics. Specifically, we analyze orbital dynamics in the…

General Relativity and Quantum Cosmology · Physics 2025-08-29 J. Horák , T. Tahamtan , T. Hale , G. Török , A. Kotrlová , E. Šrámková