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Related papers: Dressing a Naked Singularity: an Example

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We generalize here our earlier results on particle acceleration by naked singularities. We showed recently[1] that the naked singularities that form due to gravitational collapse of massive stars provide a suitable environment where…

General Relativity and Quantum Cosmology · Physics 2011-03-22 Mandar Patil , Pankaj S. Joshi , Daniele Malafarina

We investigate here the locally naked singularity formed due to a spherically symmetric inhomogeneous collapsing cloud having non-zero isotropic pressure, in terms of its strength. Sufficient condition provided by Clarke and Krolak for it…

General Relativity and Quantum Cosmology · Physics 2020-03-04 Karim Mosani , Dipanjan Dey , Pankaj S. Joshi

There are non-radial null geodesics emanating from the shell focusing singularity formed at the symmetric center in a spherically symmetric dust collapse. In this article, assuming the self-similarity in the region filled with the dust…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Ken-ichi Nakao , Naoki Kobayashi , Hideki Ishihara

In this paper, we study the instability of naked singularities arising in the Einstein equations coupled with isothermal perfect fluid. We show that the spherically symmetric self-similar naked singularities of this system, are unstable to…

General Relativity and Quantum Cosmology · Physics 2025-05-28 Junbin Li , Xi-Ping Zhu

Electromagnetic waves propagating in the background provided by a spacetime hosting a strong curvature, naked singularity, are fully studied. The analysis is performed not only in the realm of geometrical optics -- which, not surprisingly,…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Franco Fiorini , Santiago Hernandez , Juan Manuel Paez

We consider a gravastar model made of anisotropic dark energy with an infinitely thin spherical shell of a perfect fluid with the equation of state $p = (1-\gamma)\sigma$ with an external de Sitter-Schwarzschild region. It is found that in…

General Relativity and Quantum Cosmology · Physics 2015-03-17 C. F. C. Brandt , R. Chan , M. F. A. da Silva , P. Rocha

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

Perfect fluid with kinematic self-similarity is studied in 2+1 dimensional spacetimes with circular symmetry, and various exact solutions to the Einstein field equations are given. In particular, these include all the solutions of dust and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 A. Y. Miguelote , N. A. Tomimura , Anzhong Wang

Gravitational collapse of the Brans-Dicke scalar field with non-zero potential in the presence of matter fluid obeying the barotropic equation of state, $p=w\rho$ is studied. Utilizing the concept of expansion parameter, it is seen that the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 A. H. Ziaie , K. Atazadeh , Y. Tavakoli

A cylindrically symmetric perfect fluid spacetime with no curvature singularity is shown. The equation of state for the perfect fluid is that of a stiff fluid. The metric is diagonal and non-separable in comoving coordinates for the fluid.…

General Relativity and Quantum Cosmology · Physics 2009-11-10 L. Fernandez-Jambrina

We construct here a class of collapsing scalar field models with a non-zero potential, which result in a naked singularity as collapse end state. The weak energy condition is satisfied by the collapsing configuration. It is shown that…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Rituparno Goswami , Pankaj S Joshi

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

The general metric for N-dimensional spherically symmetric and conformally flat spacetimes is given, and all the homogeneous and isotropic solutions for a perfect fluid with the equation of state $p = \alpha \rho$ are found. These solutions…

General Relativity and Quantum Cosmology · Physics 2009-10-31 J. F. Villas da Rocha , Anzhong Wang

A Vaidya spacetime is considered for gravitational collapse of a type II fluid in the context of Rastall theory of gravity. For a linear equation of state (EoS) for the fluid profiles, the conditions under which the dynamical evolution of…

General Relativity and Quantum Cosmology · Physics 2020-09-11 Amir H. Ziaie , Yaser Tavakoli

The end stage of a gravitational collapse process can generically result in a black hole or a naked singularity. Here we undertake a comparative analysis of the nature of tidal forces in these backgrounds. The effect of such forces is…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Akash Goel , Reevu Maity , Pratim Roy , Tapobrata Sarkar

It is generally assumed that naked singularities must be physically excluded, as they could otherwise introduce unpredictable influences in their future null cones. Considering geodesics for a naked Reissner-Nordstrom singularity, it is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Asghar Qadir , Azad A. Siddiqui

Gravitational collapse of a spherically symmetric cloud has been extensively studied to investigate the nature of resulting singularity. However, there has been considerable debate about the admissibility of certain initial density…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. M. Antia

We discuss different kinds of Killing horizons possible in static, spherically symmetric configurations and recently classified as "usual", "naked" and "truly naked" ones depending on the near-horizon behavior of transverse tidal forces…

General Relativity and Quantum Cosmology · Physics 2009-02-23 K. A. Bronnikov , E. Elizalde , S. D. Odintsov , O. B. Zaslavskii

We consider the end state of collapsing null radiation with a string fluid. It is shown that, if diffusive transport is assumed for the string, that a naked singularity can form (at least locally). The model has the advantage of not being…

General Relativity and Quantum Cosmology · Physics 2009-11-10 K S Govinder , M Govender

The formation and semi-classical evaporation of two-dimensional black holes is studied in an exactly solvable model. Above a certain threshold energy flux, collapsing matter forms a singularity inside an apparent horizon. As the black hole…

High Energy Physics - Theory · Physics 2009-10-07 J. Russo , L. Susskind , L. Thorlacius