scholarly journals Global visibility of a strong curvature singularity in nonmarginally bound dust collapse

2020 ◽  
Vol 102 (4) ◽  
Author(s):  
Karim Mosani ◽  
Dipanjan Dey ◽  
Pankaj S. Joshi
Keyword(s):  
Curvature Singularity ◽  
Strong Curvature

scholarly journals STATIC SPHERICALLY SYMMETRIC SCALAR FIELD SPACETIMES WITH C0 MATCHING

2011 ◽  
Vol 26 (17) ◽  
pp. 1281-1290 ◽  
Author(s):  
SWASTIK BHATTACHARYA ◽  
PANKAJ S. JOSHI
Keyword(s):  
Scalar Field ◽  
Naked Singularity ◽  
Scalar Fields ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Spherically Symmetric ◽  
Curvature Singularity ◽  
Einstein Theory ◽  
Full Class ◽  
Strong Curvature

All the classes of static massless scalar field models currently available in the Einstein theory of gravity necessarily contain a strong curvature naked singularity. We obtain here a family of solutions for static massless scalar fields coupled to gravity, which does not have any strong curvature singularity. This class of models contain a thin shell of singular matter, which has a physical interpretation. The central curvature singularity is, however, avoided which is common to all static massless scalar field spacetime models known so far. Our result thus points out that the full class of solutions in this case may contain non-singular models, which is an intriguing possibility.

scholarly journals GENERALIZED STRONG CURVATURE SINGULARITIES AND COSMIC CENSORSHIP

2002 ◽  
Vol 17 (07) ◽  
pp. 387-397 ◽  
Author(s):  
WIESŁAW RUDNICKI ◽  
ROBERT J. BUDZYŃSKI ◽  
WITOLD KONDRACKI
Keyword(s):  
Causal Structure ◽  
Cosmic Censorship ◽  
Single Type ◽  
Curvature Singularity ◽  
Cosmic Censorship Hypothesis ◽  
Definition Of ◽  
Strong Curvature

A new definition of a strong curvature singularity is proposed. This definition is motivated by the definitions given by Tipler and Królak, but is significantly different and more general. All causal geodesics terminating at these new singularities, which we call generalized strong curvature singularities, are classified into three possible types; the classification is based on certain relations between the causal structure and the curvature strength of the singularities. A cosmic censorship theorem is formulated and proved which shows that only one class of generalized strong curvature singularities, corresponding to a single type of geodesics according to our classification, can be naked. Implications of this result for the cosmic censorship hypothesis are indicated.

HIGHER DIMENSIONAL CHARGED NULL FLUID COLLAPSE AND COSMIC CENSORSHIP

2002 ◽  
Vol 11 (02) ◽  
pp. 237-244 ◽  
Author(s):  
S. G. GHOSH ◽  
R. V. SARAYKAR
Keyword(s):  
Black Holes ◽  
Energy Condition ◽  
Cosmic Censorship ◽  
Final Outcome ◽  
Spherically Symmetric ◽  
Curvature Singularity ◽  
Naked Singularities ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Strong Curvature

We analyze here the spherically symmetric collapse of a charged null fluid in a higher dimensional spacetime. Both naked singularities and black holes are shown to be developing as final outcome of the collapse. A relationship between weak energy condition and occurrence of strong curvature singularity is pointed out.

scholarly journals SINGULARITY IN GRAVITATIONAL COLLAPSE OF PLANE SYMMETRIC CHARGED VAIDYA SPACETIME

2010 ◽  
Vol 25 (33) ◽  
pp. 2831-2836 ◽  
Author(s):  
M. SHARIF ◽  
AISHA SIDDIQA
Keyword(s):  
Gravitational Collapse ◽  
Energy Condition ◽  
Cosmic Censorship ◽  
Final Outcome ◽  
Curvature Singularity ◽  
Field Equations ◽  
Plane Symmetric ◽  
Counter Example ◽  
Cosmic Censorship Hypothesis ◽  
Strong Curvature

We study the final outcome of gravitational collapse resulting from the plane symmetric charged Vaidya spacetime. Using the field equations, we show that the weak energy condition is always satisfied by collapsing fluid. It is found that the singularity formed is naked. The strength of singularity is also investigated by using Nolan's method. This turns out to be a strong curvature singularity in Tipler's sense and hence provides a counter example to the cosmic censorship hypothesis.

scholarly journals A substrate for brane shells from $$ T\overline{T} $$

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Jeremias Aguilera-Damia ◽  
Louise M. Anderson ◽  
Evan Coleman
Keyword(s):  
Three Dimensional ◽  
Radial Position ◽  
Singular Behavior ◽  
Curvature Singularity ◽  
Closed Timelike Curves ◽  
Finite Radius ◽  
Linear Dilaton ◽  
Singularity Resolution ◽  
New Interpretation ◽  
Single Trace

Abstract A solvable current-current deformation of the worldsheet theory of strings on AdS3 has been recently conjectured to be dual to an irrelevant deformation of the spacetime orbifold CFT, commonly referred to as single-trace $$ T\overline{T} $$ T T ¯ . These deformations give rise to a family of bulk geometries which realize a non-trivial flow towards the UV. For a particular sign of this deformation, the corresponding three-dimensional geometry approaches AdS3 in the interior, but has a curvature singularity at finite radius, beyond which there are closed timelike curves. It has been suggested that this singularity is due to the presence of “negative branes,” which are exotic objects that generically change the metric signature. We propose an alternative UV-completion for geometries displaying a similar singular behavior by cutting and gluing to a regular background which approaches a linear dilaton vacuum in the UV. In the S-dual picture, a singularity resolution mechanism known as the enhançon induces this transition by the formation of a shell of D5-branes at a fixed radial position near the singularity. The solutions involving negative branes gain a new interpretation in this context.

scholarly journals Cylindrically Symmetric, Asymptotically Flat, Petrov Type D Spacetime with a Naked Curvature Singularity and Matter Collapse

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Faizuddin Ahmed
Keyword(s):  
Cosmic Time ◽  
Petrov Type ◽  
Energy Conditions ◽  
Anisotropic Fluid ◽  
Curvature Singularity ◽  
Field Equations ◽  
Asymptotically Flat ◽  
Type D ◽  
Cylindrically Symmetric ◽  
Petrov Type D

We present a cylindrically symmetric, Petrov type D, nonexpanding, shear-free, and vorticity-free solution of Einstein’s field equations. The spacetime is asymptotically flat radially and regular everywhere except on the symmetry axis where it possesses a naked curvature singularity. The energy-momentum tensor of the spacetime is that for an anisotropic fluid which satisfies the different energy conditions. This spacetime is used to generate a rotating spacetime which admits closed timelike curves and may represent a Cosmic Time Machine.

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