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Related papers: Generalized JMN Naked Singularity Models

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We extend the method of Simpson and Visser (SV) of regularising a black hole spacetime, to cases where the initial metric represents a globally naked singularity. We choose two particular geometries, the Janis-Newman-Winicour (JNW) metric…

General Relativity and Quantum Cosmology · Physics 2023-05-31 Kunal Pal , Kuntal Pal , Pratim Roy , Tapobrata Sarkar

It is generally believed that the shadows of either a black hole or naked singularity arise due to photon spheres developing in these spacetimes. Here we propose a new spherically symmetric naked singularity spacetime solution of Einstein…

General Relativity and Quantum Cosmology · Physics 2020-07-15 Ashok B. Joshi , Dipanjan Dey , Pankaj S. Joshi , Parth Bambhaniya

We present the first three-dimensional general relativistic magnetohydrodynamic simulation of sustained accretion onto a horizonless singularity in which matter reaches the central object rather than being accumulated outside of it or…

High Energy Astrophysical Phenomena · Physics 2026-04-20 Saurabh , Maciek Wielgus , Parth Bambhaniya , Elisabete M. de Gouveia Dal Pino , Andrei P. Lobanov , Pankaj S. Joshi

In the present paper, we study the thermal properties of the geometrically thin accretion disks surrounding the null naked singularity (NNS) and the first type of Joshi-Malafarina-Narayan (JMN1) spacetimes and compare the results with the…

General Relativity and Quantum Cosmology · Physics 2022-08-31 Divya Tahelyani , Ashok B. Joshi , Dipanjan Dey , Pankaj S. Joshi

Recent Event Horizon Telescope observations of M87* and Sgr A* strongly suggests the presence of supermassive black hole at their respective cores. In this work, we use the semi-analytic Radiatively Inefficient Accretion Flows (RIAF) model…

High Energy Astrophysical Phenomena · Physics 2024-02-08 Saurabh , Parth Bambhaniya , Pankaj S. Joshi

We compare shadows cast by Schwarzschild black holes with those produced by two classes of naked singularities that result from gravitational collapse of spherically symmetric matter. The latter models consist of an interior naked…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Rajibul Shaikh , Prashant Kocherlakota , Ramesh Narayan , Pankaj S. Joshi

We formulate a generic Newtonian like analogous potential for static spherically symmetric general relativistic (GR) spacetime, and subsequently derived proper Newtonian like analogous potential corresponding to Janis-Newman-Winicour (JNW)…

General Relativity and Quantum Cosmology · Physics 2015-11-09 Shubhrangshu Ghosh , Tamal Sarkar , Arunava Bhadra

It is now theoretically well established that not only a black hole can cast shadow, but other compact objects such as naked singularities, gravastar or boson stars can also cast shadows. An intriguing fact that has emerged is that the…

General Relativity and Quantum Cosmology · Physics 2021-06-25 Kanwar Preet Kaur , Pankaj S. Joshi , Dipanjan Dey , Ashok B. Joshi , Rucha P. Desai

We analyze the causal structure of horizonless compact objects via the light-cone geometry and conformal compactification of the Joshi-Malafarina-Narayan (JMN-1) and Janis-Newman-Winicour (JNW) spacetimes. Penrose diagrams reveal that JMN-1…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Bina Patel , Jahnvi Mistry , Ayush Bidlan , Parth Bambhaniya

In this paper, we study the quasinormal modes of the generalized Joshi-Malafarina-Narayan (JMN) naked singularity spacetime using the exact Wentzel-Kramers-Brillouin (WKB) method. Working in the complex radial plane, we construct the exact…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Aryansh Saxena , Suresh C. Jaryal , K. K. Sharma

Theoretical studies suggest that gravitational collapse can form either a black hole or a visible (naked) singularity. Identifying observational signatures that distinguish these two types of collapsed objects is a holy grail of physics.…

High Energy Astrophysical Phenomena · Physics 2026-03-24 Vishva Patel , Sayantan Bhattacharya , Sudip Bhattacharyya , Pankaj S. Joshi

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

In this paper, we perform a comprehensive analysis of the quasinormal modes in an external geometry of the Joshi-Malafarina-Narayan (JMN-1) naked singularity by investigating its response to linear perturbations, including gravitational and…

General Relativity and Quantum Cosmology · Physics 2025-09-11 Akshat Pathrikar , Parth Bambhaniya , Pankaj S. Joshi , Elisabete M. de Gouveia Dal Pino

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

Generalizing earlier results of Joshi and Dwivedi (Commun. Math. Phys. 146, 333 (1992); Lett. Math. Phys. 27, 235 (1993)), we analyze here the spherically symmetric gravitational collapse of a matter cloud with a general form of matter for…

General Relativity and Quantum Cosmology · Physics 2009-10-22 I. H. Dwivedi , P. S. Joshi

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 investigate here the genericity and stability aspects for naked singularities and black holes that arise as the final states for a complete gravitational collapse of a spherical massive matter cloud. The form of the matter considered is…

General Relativity and Quantum Cosmology · Physics 2012-11-15 Pankaj S. Joshi , Daniele Malafarina , Ravindra V. Saraykar

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

We investigate whether a timelike naked singularity of negative-mass Schwarzschild type can be causally dressed by a static anisotropic matter distribution in classical general relativity. Working within a spherically symmetric framework,…

General Relativity and Quantum Cosmology · Physics 2026-05-19 Pablo León , G. Alencar , Manuel Gonzalez-Espinoza , Francisco Tello-Ortiz

We study here the structure of singularity forming in gravitational collapse of spherically symmetric inhomogeneous dust. Such a collapse is described by the Tolman-Bondi-Lema{\^i}tre metric, which is a two-parameter family of solutions to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Jhingan , P. S. Joshi
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