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

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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

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 causal character of the zero-areal-radius (R=0) singularity in spherically symmetric spacetimes is studied. By using the techniques of the qualitative behaviour of dynamic systems, we are able to present the most comprehensive scheme so…

General Relativity and Quantum Cosmology · Physics 2012-04-23 Francesc Fayos , Ramon Torres

The complete spectrum of the endstates - naked singularities, or blackholes - of gravitational collapse is analyzed for a wide class of $N$-dimensional spacetimes in spherical symmetry, which includes and generalizes the dust solutions and…

General Relativity and Quantum Cosmology · Physics 2010-03-24 Roberto Giambó , Sara Quintavalle

In the present work some generalizations of the Hawking singularity theorems in the context of $f(R)$ theories are presented. The assumptions are of these generalized theorems is that the matter fields satisfy the conditions…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Ivo Alani , Osvaldo Santillan

We investigate here spherically symmetric gravitational collapse in a spacetime with an arbitrary number of dimensions and with a general {\it type I} matter field, which is a broad class that includes most of the physically reasonable…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Rituparno Goswami , Pankaj S Joshi

There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Singh

It is shown that a scalar field, minimally coupled to gravity may have collapsing modes even when the energy condition is violated, that is, for $(\rho+3p)<0$. This result may be useful in the investigation of the possible clustering of…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Koyel Ganguly , Narayan Banerjee

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

We construct an approximate solution which describes the gravitational emission from a naked singularity formed by the gravitational collapse of a cylindrical thick shell composed of dust. The assumed situation is that the collapsing speed…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Ken-ichi Nakao , Yoshiyuki Morisawa

The possible violation of the weak cosmic censorship hypothesis in astrophysical phenomena can provide us with the information about trans-Planckian physics through observations. We present negative evidence, however, that one should not…

General Relativity and Quantum Cosmology · Physics 2013-05-24 Umpei Miyamoto , Sanjay Jhingan , Tomohiro Harada

Gravitational collapse of radiation in an anti-de Sitter background is studied. For the spherical case, the collapse proceeds in much the same way as in the Minkowski background, i.e., massless naked singularities may form for a highly…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jose' P. S. Lemos

The objective of the present paper is to study 4-dimensional weakly Ricci symmetric spacetimes $(WRS)_4$ with non-zero constant Ricci scalar. We prove that such a $(WRS)_4$ satisfying $F(R)$-gravity field equations represents a perfect…

General Relativity and Quantum Cosmology · Physics 2021-03-30 Avik De , Tee-How Loo , Simran Arora , P. K. Sahoo

We discuss the gravitational collapse of a spherically symmetric massive core of a star in which the fluid component is interacting with a growing vacuum energy density. The influence of the variable vacuum in the collapsing core is…

General Relativity and Quantum Cosmology · Physics 2015-06-05 M. Campos , J. A. S. Lima

We study gravitational collapse of the general spherically symmetric null strange quark fluid having the equation of state, $p = (\rho - 4B)/n$, where $B$ is the bag constant. An interesting feature that emerges is that the initial data set…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. G. Ghosh , Naresh Dadhich

We investigate the occurrence and nature of a naked singularity in the gravitational collapse of an inhomogeneous dust cloud described by higher dimensional Tolman-Bondi space-time. The naked singularities are found to be gravitationally…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ujjal Debnath , Subenoy Chakraborty

It is shown that gauged nonlinear sigma models can be always deformed by terms proportional to the field strength of the gauge fields (nonminimal gauging). These deformations can be interpreted as perturbations, by marginal operators, of…

High Energy Physics - Theory · Physics 2009-10-22 Noureddine Mohammedi

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 issue of local versus the global visibility of a singularity that forms in gravitational collapse of a dust cloud, which has important implications for the weak and strong versions of the cosmic censorship hypothesis. We…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. S. Deshingkar , S. Jhingan , P. S. Joshi

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
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