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Related papers: Naked Singularity Formation In f(R) Gravity

200 papers

We investigate the formation of a locally naked singularity in the collapse of radiation shells in an expanding Vaidya-deSitter background. This is achieved by considering the behaviour of non-spacelike and radial geodesics originating at…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. M. Wagh , S. D. Maharaj

We consider a spherically symmetric homogeneous perfect fluid undergoing a gravitational collapse to singularity in the framework of higher-dimensional Rastall gravity in the cases of vanishing and nonvanishing cosmological constants. The…

General Relativity and Quantum Cosmology · Physics 2025-04-08 Golfin Ekatria , Andy Octavian Latief , Fiki Taufik Akbar , Bobby Eka Gunara

We perform a careful investigation of the problem of physically realistic gravitational collapse of massive stars in f(R)-gravity. We show that the extra matching conditions that arise in the modified gravity imposes strong constraints on…

General Relativity and Quantum Cosmology · Physics 2014-10-15 Rituparno Goswami , Anne Marie Nzioki , Sunil. D. Maharaj , Sushant G. Ghosh

In this paper, we investigate the nature of the singularity in the spherically symmetrical, shear-free, gravitational collapse of a star with heat flux using a separable metric [cqg1]. For any non-singular, regular, radial density profile…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. M. Wagh , R. V. Saraykar , P. S. Muktibodh , K. S. Govinder

The gravitational collapse of a thick cylindrical shell of dust matter is investigated. It is found that a spacetime singularity forms on the symmetry axis and that it is necessarily naked, i.e., observable in principle. We propose a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ken-ichi Nakao , Yasunari Kurita , Yoshiyuki Morisawa , Tomohiro Harada

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

In this paper, we investigate spherically symmetric perfect fluid gravitational collapse in metric $f(R)$ gravity. We take non-static spherically symmetric metric in the interior region and static spherically symmetric metric in the…

General Relativity and Quantum Cosmology · Physics 2011-01-17 M. Sharif , H. Rizwana Kausar

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

A naked singularity is formed by the collapse of a Sine-Gordon soliton in 1+1 dimensional dilaton gravity with a negative cosmological constant. We examine the quantum stress tensor resulting from the formation of the singularity.…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Cenalo Vaz , Louis Witten

The gravitational collapse of spherical, barotropic perfect fluids is analyzed here. For the first time, the final state of these systems is studied without resorting to simplifying assumptions - such as self-similarity - using a new…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Roberto Giambo' , Fabio Giannoni , Giulio Magli , Paolo Piccione

Alternatives to Einstein's theory of general relativity can be distinguished by measuring the parametrised post Newtonian parameters. Two such parameters $\beta$ and $\gamma$, equal to one in Einstein theory, can be obtained from static…

High Energy Physics - Theory · Physics 2008-02-03 S. Kalyana Rama

The Janis-Newman-Winicour (JNW) spacetime possesses a naked singularity, although it represents an exact particle-like solution to the Einstein-Klein-Gordon theory with a massless scalar field. Here, we investigate the possible formation of…

General Relativity and Quantum Cosmology · Physics 2024-08-07 Xiao Yan Chew , Il Gyeong Choi , Hyuk Jung Kim , Dong-han Yeom

Within the framework of the scalar-tensor models of gravitation and by relying on analytical and numerical techniques, we establish the existence of a class of spherically symmetric spacetimes containing a naked singularity. Our result…

General Relativity and Quantum Cosmology · Physics 2010-11-30 Nabil Bedjaoui , Philippe G. LeFloch , José M. Martín-García , Jérôme Novak

According to the cosmic censorship hypothesis of Penrose, naked singularities should never occur in realistic collapse situations. One of the major open problems in this context is the existence of a naked singularity in the Kerr solution…

General Relativity and Quantum Cosmology · Physics 2009-10-30 W. Rudnicki

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 consider the problem of collapse of a self-gravitating Higgs field, with potential bounded below by a (possibly negative) constant. The behaviour at infinity may be either asymptotically flat or asymptotically AdS. This problem has…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mihalis Dafermos

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

We model massive compact objects in galactic nuclei as stationary, axially-symmetric naked singularities in the Einstein-massless scalar field theory and study the resulting gravitational lensing. In the weak deflection limit we study…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Galin N. Gyulchev , Stoytcho S. Yazadjiev

The gravitational dynamics of a collapsing matter configuration which is simultaneously radiating heat flux is studied in $f(R)$ gravity. Three particular functional forms in $f(R)$ gravity are considered to show that it is possible to…

General Relativity and Quantum Cosmology · Physics 2021-04-05 Ayan Chatterjee , Suresh C. Jaryal

The cosmological constant induced by quantum fluctuation of the graviton on a given background is considered as a tool for building a spectrum of different geometries. In particular, we apply the method to the Schwarzschild background with…

General Relativity and Quantum Cosmology · Physics 2009-07-24 Remo Garattini