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Generalizing earlier results on the initial data and the final fate of dust collapse, we study here the relevance of the initial state of a spherically symmetric matter cloud towards determining its end state in the course of a continuing…

General Relativity and Quantum Cosmology · Physics 2009-10-31 P. S. Joshi , I. H. Dwivedi

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

It is now known that when a massive star collapses under the force of its own gravity, the final fate of such a continual gravitational collapse will be either a black hole or a naked singularity under a wide variety of physically…

General Relativity and Quantum Cosmology · Physics 2012-04-20 Pankaj S. Joshi , Daniele Malafarina

We analyze here the structure of non-radial nonspacelike geodesics terminating in the past at a naked singularity formed as the end state of inhomogeneous dust collapse. The spectrum of outgoing nonspacelike null geodesics is examined…

General Relativity and Quantum Cosmology · Physics 2009-11-07 S. S. Deshingkar , P. S. Joshi , I. H. Dwivedi

We study the complete gravitational collapse of a class of spherically symmetric inhomogeneous perfect fluid models obtained by introducing small radial perturbations in an otherwise homogeneous matter cloud. Our aim here is to study the…

General Relativity and Quantum Cosmology · Physics 2016-03-10 Seema Satin , Daniele Malafarina , Pankaj S. Joshi

We give a characterization of the central shell-focusing curvature singularity that can form in the spherical gravitational collapse of a bounded matter distribution obeying the dominant energy condition. This characterization is based on…

General Relativity and Quantum Cosmology · Physics 2009-10-31 T. P. Singh

We consider here the effects of a non-vanishing cosmological term on the final fate of a spherical inhomogeneous collapsing dust cloud. It is shown that depending on the nature of the initial data from which the collapse evolves, and for a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 S. S. Deshingkar , S. Jhingan , A. Chamorro , P. S. Joshi

We investigate what are the key physical features that cause the development of a naked singularity, rather than a black hole, as the end-state of spherical gravitational collapse. We show that sufficiently strong shearing effects near the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Pankaj S. Joshi , Naresh Dadhich , Roy Maartens

We present here an overview of our basic understanding and recent developments on spacetime singularities in the Einstein theory of gravity. Several issues related to physical significance and implications of singularities are discussed.…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Pankaj S. Joshi

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

We study here the gravitational collapse of a matter cloud with a non-vanishing tangential pressure in the presence of a non-zero cosmological term. Conditions for bounce and singularity formation are derived for the model. It is also shown…

General Relativity and Quantum Cosmology · Physics 2015-06-25 T. Arun Madhav , Rituparno Goswami , Pankaj S. Joshi

We explore semiclassical stellar collapse scenarios with pressure within the framework of effective loop quantum gravity. The objective of this work is to generalize existent models of semiclassical dust collapse and examine the role of…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Luca Cafaro , Lorenzo Cipriani , Francesco Fazzini , Farshid Soltani

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 phase space corresponding to a particular four-parameter family of initial data for the gravitational collapse of a spherically symmetric dust cloud is investigated. In a certain limit of the parameters, this family reproduces the case…

General Relativity and Quantum Cosmology · Physics 2015-03-20 Néstor Ortiz

At the threshold of black hole formation in the gravitational collapse of a scalar field a naked singularity is formed through a universal critical solution that is discretely self-similar. We study the global spacetime structure of this…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jose M. Martin-Garcia , Carsten Gundlach

We consider spherically symmetric spacetimes with matter whose timelike flow is assumed to be shear-free. A number of results on the formation and visibility of spacetime singularities is proven, with the main one being that shear-free…

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

The final state of the gravitational collapse of a marginally bound dust cloud is formulated in terms of an existence problem for the non-linear differential equation governing radial null geodesics near the singular point. Rigorous results…

Mathematical Physics · Physics 2014-08-07 Roberto Giambo' , Giulio Magli

In general relativity, gravitational collapse of matter fields ends with the formation of a spacetime singularity, where the matter density becomes infinite and standard physics breaks down. According to the weak cosmic censorship…

General Relativity and Quantum Cosmology · Physics 2014-08-05 Lingyao Kong , Daniele Malafarina , Cosimo Bambi

Gravitational collapse is one of the most fruitful subjects in gravitational physics. It is well known that singularity formation is inevitable in complete gravitational collapse. It was conjectured that such a singularity should be hidden…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Tomohiro Harada , Hideo Iguchi , Ken-ichi Nakao

The study of dynamic singularity formation in spacetime, focusing on scalar field collapse models, is analysed. We revisit key findings regarding open spatial topologies, concentrating on minimal conditions necessary for singularity and…

General Relativity and Quantum Cosmology · Physics 2024-05-10 Dario Corona , Roberto Giambò