English
Related papers

Related papers: Scalar Radiation in the Background of a Naked Sing…

200 papers

Considering a strong field limit, we investigate the retrolensing phenomenon in the vicinity of a Janis-Newman-Winicour (JNW) naked singularity embedded in a scalar field. We assume that the light rays from a nearby source are reflected by…

General Relativity and Quantum Cosmology · Physics 2021-12-07 Gulmina Zaman Babar , Farruh Atamurotov , Abdullah Zaman Babar , Yen-Kheng Lim

The Janis-Newman-Winicour (JNW) spacetime can describe a naked singularity with a photon sphere that smoothly transforms into a Schwarzschild black hole. Our analysis reveals that photons, upon entering the photon sphere, converge to the…

General Relativity and Quantum Cosmology · Physics 2023-09-20 Deyou Chen , Yiqian Chen , Peng Wang , Tianshu Wu , Houwen Wu

Though the cosmic censorship conjecture states that spacetime singularities must be hidden from an asymptotic observer by an event horizon, naked singularities can form as the end product of a gravitational collapse under suitable initial…

General Relativity and Quantum Cosmology · Physics 2020-12-24 Avijit Chowdhury , Narayan Banerjee

This paper explores the unique observational signatures of accretion onto a Janis-Newman-Winicour (JNW) strongly naked singularity, particularly in the absence of a photon sphere. The surrounding spacetime of such a singularity exhibits…

General Relativity and Quantum Cosmology · Physics 2025-05-20 Zeqian Zhang

It is commonly thought that the final product of gravitational collapse is a black hole. Nevertheless, theoretical studies have not yet provided a final answer to the question whether black holes are the only possible outcome or whether…

General Relativity and Quantum Cosmology · Physics 2018-08-31 Honghui Liu , Menglei Zhou , Cosimo Bambi

In this paper, we investigated the motion of massive particles in the presence of scalar and gravitational fields, particularly focusing on the Janis-Newman-Winicour (JNW) naked singularity solution. It is shown that the innermost stable…

General Relativity and Quantum Cosmology · Physics 2024-09-11 Bobur Turimov , Akbar Davlataliev , Ahmadjon Abdujabbarov , Bobomurat Ahmedov

The final fate of gravitational collapse of massive stars has been a subject of interest for a long time since such a collapse may lead to black holes and naked singularities alike. Since, the formation of naked singularities is forbidden…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Subhadip Sau , Indrani Banerjee , Soumitra SenGupta

We analyze the scalar radiation emitted by a source in a circular geodesic orbit around a spherically symmetric black hole. The black hole spacetime considered is quite general, in the sense that it encompasses the solutions of…

General Relativity and Quantum Cosmology · Physics 2020-04-21 Rafael Bernar

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

The scalar radiation emitted by a source in geodesic circular orbit around a regular Bardeen black hole is analyzed. We use the quantum field theory in curved spacetime framework to obtain the emitted power of radiation by computing the…

General Relativity and Quantum Cosmology · Physics 2019-07-17 R. P. Bernar , L. C. B. Crispino

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

We investigate the radiation emitted from a scalar source in circular orbit around a Reissner-Nordstrom black hole. Particle and energy emission rates are analytically calculated in the low- and high-frequency regimes and shown to be in…

General Relativity and Quantum Cosmology · Physics 2009-01-16 Luis C. B. Crispino , Andre R. R. da Silva , George E. A. Matsas

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 analyze the scalar radiation emitted from a source rotating around a Schwarzschild black hole using the framework of quantum field theory at the tree level. We show that for relativistic circular orbits the emitted power is about 20% to…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Luis C. B. Crispino , Atsushi Higuchi , George E. A. Matsas

In the final stages of collapse, quantum radiation due to particle creation from a naked singularity is expected to be significantly different from black hole radiation. In certain models of collapse it has been shown that, neglecting the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Cenalo Vaz , Louis Witten

Scalar--tensor theories of gravity provide a natural extension of general relativity and may predict naked singularities as alternative compact objects. In this work, we investigate a novel exact solution within the Freud--Nambu…

General Relativity and Quantum Cosmology · Physics 2026-03-13 Akbar Davlataliev , Bobur Turimov , Bobomurat Ahmedov , Yuri Vyblyi , Chengxun Yuan , Chen Zhou

We study the optical appearance and the apparent radiation flux of a thin accretion disk around the static Janis-Newman-Winicour naked singularity. We confine ourselves to the astrophysically most relevant case, when the solution possesses…

General Relativity and Quantum Cosmology · Physics 2019-07-31 Galin Gyulchev , Petya Nedkova , Tsvetan Vetsov , Stoytcho Yazadjiev

We study the linear polarization from the accretion disk around weakly and strongly naked Janis-Newman-Winicour singularities. We consider an analytical toy model of thin magnetized fluid ring orbiting in the equatorial plane and emitting…

General Relativity and Quantum Cosmology · Physics 2023-03-28 Valentin Deliyski , Galin Gyulchev , Petya Nedkova , Stoytcho Yazadjiev

We study the gravitational deflection of relativistic massive particles by Janis-Newman-Winicour (JNW) spacetimes (also known as a rotating source with a surface-like naked singularity), and a rotating Kerr-like wormholes. Based on the…

General Relativity and Quantum Cosmology · Physics 2019-01-17 Kimet Jusufi , Ayan Banerjee , Galin Gyulchev , Muhammed Amir

In this paper, we construct the rotating Janis-Newman-Winicour (JNW) naked singularity spacetime using Newman-Janis Algorithm (NJA). We analyse NJA with and without complexification methods and find that the energy conditions do satisfied…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Divyesh N. Solanki , Parth Bambhaniya , Dipanjan Dey , Pankaj S. Joshi , Kamlesh N. Pathak
‹ Prev 1 2 3 10 Next ›