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Related papers: Physical Processes in Naked Singularity Formation

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There are many solutions to the Einstein field equations that demonstrate naked singularity (NS) formation after regular evolution. It is possible, however, that such a quantum effect as particle creation prevents NSs from forming. We…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Umpei Miyamoto , Hideki Maeda , Tomohiro Harada

We investigate the occurrence and nature of naked singularities in the gravitational collapse of a self-similar adiabatic perfect fluid in a five dimensional space-time. The naked singularities are found to be gravitationally strong in the…

General Relativity and Quantum Cosmology · Physics 2015-06-23 S G Ghosh , S B Sarwe , R V Saraykar

Gravitational collapse singularities are undesirable, yet inevitable to a large extent in General Relativity. When matter satisfying null energy condition collapses to the extent a closed trapped surface is formed, a singularity is…

General Relativity and Quantum Cosmology · Physics 2020-03-09 Karthik H. Shankar

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

We derive an equation for the acceleration of a fluid element in the spherical gravitational collapse of a bounded compact object made up of an imperfect fluid. We show that non-singular as well as singular solutions arise in the collapse…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Sukratu Barve , T. P. Singh , Louis Witten

We investigate the occurrence of naked singularities, local and global, in the incoming Vaidya spacetimes with zero initial mass. While it is well-known that these spacetimes admit locally and globally naked singularities, we demonstrate…

General Relativity and Quantum Cosmology · Physics 2022-09-20 James Wheeler

We study the gravitational collapse of a star with barotropic equation of state $p=w\rho$ in the context of $f({\mathcal R})$ theories of gravity. Utilizing the metric formalism, we rewrite the field equations as those of Brans-Dicke theory…

General Relativity and Quantum Cosmology · Physics 2015-05-28 A. H. Ziaie , K. Atazadeh , S. M. M. Rasouli

Naked singularities form during the gravitational collapse of inhomogeneous matter clouds. The final nature of the singularity depends on the initial conditions of the matter properties and types of matter profiles. These naked…

General Relativity and Quantum Cosmology · Physics 2022-06-01 Siddharth Madan , Parth Bambhaniya

The density fluctuations in the nearly homogeneous background in the very early universe are argued to be the origin of the cosmic structures we observe in our present universe. Along with many other structures, these fluctuations would…

General Relativity and Quantum Cosmology · Physics 2025-07-23 Koushiki , Pankaj S. Joshi , Sudip Bhattacharyya

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 2015-03-19 R. Chan , M. F. A. da Silva , P. Senna , J. F. Villas da Rocha

Considering gravitational collapse of matter, it is important problem to clarify what kind of conditions leads to the formation of naked singularity. For this purpose, we apply the 1+3 orthonormal frame formalism introduced by Uggla…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Hayato Kawakami , Eiji Mitsuda , Yasusada Nambu , Akira Tomimatsu

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

For a wide class of spherically symmetric naked singularities there is a sphere within which gravity is effectively repulsive. In such spacetimes accreting matter cannot reach the singularity and will instead form a levitating atmosphere,…

General Relativity and Quantum Cosmology · Physics 2021-09-07 Ronaldo S. S. Vieira , Włodek Kluźniak

We study spherically symmetric gravitational collapse of a homogeneous perfect fluid in Rastall gravity. Considering a linear equation of state (EoS) for the fluid profiles, we examine the conditions under which the collapse scenario could…

General Relativity and Quantum Cosmology · Physics 2019-05-08 A. H. Ziaie , H. Moradpour , S. Ghaffari

We analyze spherical dust collapse with non-vanishing radial pressure, $\Pi$, and vanishing tangential stresses. Considering a barotropic equation of state, $\Pi=\gamma\rho$, we obtain an analytical solution in closed form---which is exact…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Sergio M. C. V. Goncalves , Sanjay Jhingan

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

We consider a static, axially symmetric, and asymptotically flat exact solution of the Einstein vacuum equations, known as the gamma metric. This is characterized by two constant parameters $m$ and $\gamma$. We find that the total energy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 K. S. Virbhadra

The present work investigates the gravitational collapse of a perfect fluid in $f(R)$ gravity models. For a general $f(R)$ theory, it is shown analytically that a collapse is quite possible. The singularity formed as a result of the…

General Relativity and Quantum Cosmology · Physics 2016-03-30 Soumya Chakrabarti , Narayan Banerjee

Gravitational collapse of radiation shells in a non self-similar higher dimensional spherically symmetric spacetime is studied. Strong curvature naked singularities form for a highly inhomogeneous collapse, violating the cosmic censorship…

General Relativity and Quantum Cosmology · Physics 2009-11-07 S G Ghosh , R V Saraykar , A Beesham

The existence of spacetime singularities is one of the biggest problems of nowadays physics. According to Penrose, each physical singularity should be covered by a "cosmic censor" which prevents any external observer from perceiving their…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Alfio Bonanno , Benjamin Koch , Alessia Platania