NATURE OF THE SINGULARITIES IN HIGHER-DIMENSIONAL HUSAIN SPACE–TIME

2006 ◽  
Vol 15 (09) ◽  
pp. 1359-1371 ◽  
Author(s):  
K. D. PATIL ◽  
S. S. ZADE

We generalize the earlier studies on the spherically symmetric gravitational collapse in four-dimensional space–time to higher dimensions. It is found that the central singularities may be naked in higher dimensions but depend sensitively on the choices of the parameters. These naked singularities are found to be gravitationally strong that violate the cosmic censorship hypothesis.

2001 ◽  
Vol 16 (27) ◽  
pp. 4481-4488 ◽  
Author(s):  
S. G. GHOSH ◽  
R. V. SARAYKAR ◽  
A. BEESHAM

Gravitational collapse of radiation shells in a non-self-similar higher dimensional spherically symmetric space–time is studied. Strong curvature naked singularities form a highly inhomogeneous collapse, violating the cosmic censorship conjecture. As a special case, self similar models can be constructed.


2011 ◽  
Vol 20 (12) ◽  
pp. 2317-2335 ◽  
Author(s):  
KANG ZHOU ◽  
ZHAN-YING YANG ◽  
DE-CHENG ZOU ◽  
RUI-HONG YUE

We investigate the spherically symmetric gravitational collapse of an incoherent dust cloud by considering a LTB-type spacetime in third-order Lovelock Gravity without cosmological constant, and give three families of LTB-like solutions which separately corresponding to hyperbolic, parabolic and elliptic. Notice that the contribution of high-order curvature corrections have a profound influence on the nature of the singularity, and the global structure of spacetime changes drastically from the analogous general relativistic case. Interestingly, the presence of high order Lovelock terms leads to the formation of massive, naked and timelike singularities in the 7D spacetime, which is disallowed in general relativity. Moveover, we point out that the naked singularities in the 7D case may be gravitational weak therefore may not be a serious threat to the cosmic censorship hypothesis, while the naked singularities in the D ≥ 8 inhomogeneous collapse violate the cosmic censorship hypothesis seriously.


2003 ◽  
Vol 12 (05) ◽  
pp. 913-924 ◽  
Author(s):  
S. G. GHOSH ◽  
D. W. DESHKAR

We investigate the occurrence and nature of naked singularities in the gravitational collapse of an adiabatic perfect fluid in self-similar higher dimensional space–times. It is shown that strong curvature naked singularities could occur if the weak energy condition holds. Its implication for cosmic censorship conjecture is discussed. Known results of analogous studies in four dimensions can be recovered.


2003 ◽  
Vol 12 (04) ◽  
pp. 639-648 ◽  
Author(s):  
S. G. GHOSH ◽  
A. BANERJEE

We investigate the occurrence and nature of a naked singularity in the gravitational collapse of an inhomogeneous dust cloud described by a self-similar higher dimensional Tolman–Bondi space–time. Bound, marginally bound and unbound space–times are analyzed. The degree of inhomogeneity of the collapsing matter necessary to form a naked singularity is given.


1992 ◽  
Vol 07 (08) ◽  
pp. 653-658 ◽  
Author(s):  
SUBENOY CHAKRABORTY

The wave function following the Hartle-Hawking (HH) no-boundary proposal is evaluated in five-dimensional space-time with topology of the four space S1×S3, generalizing the concept of microsuperspace. The functional integral in the expression for the wave function is simplified to an ordinary integration of one variable and is evaluated by the method of steepest-descent.


2003 ◽  
Vol 12 (07) ◽  
pp. 1255-1263 ◽  
Author(s):  
ASIT BANERJEE ◽  
UJJAL DEBNATH ◽  
SUBENOY CHAKRABORTY

Spherically symmetric inhomogeneous dust collapse has been studied in higher dimensional space–time and the factors responsible for the appearance of a naked singularity are analyzed in the region close to the centre for the marginally bound case. It is clearly demonstrated that in the former case naked singularities do not appear in the space–time having more than five dimension, which appears to a strong result. The non-marginally bound collapse is also examined in five dimensions and the role of shear in developing naked singularities in this space–time is discussed in details. The five-dimensional space–time is chosen in the later case because we have exact solution in closed form only in five dimension and not in any other case.


2004 ◽  
Vol 13 (02) ◽  
pp. 229-238 ◽  
Author(s):  
B. C. PAUL

A class of relativistic solutions of compact star which is in hydrostatic equilibrium is obtained in higher dimensions assuming a spherically symmetric space–time. The space–time geometry is assumed to be a (D-1)-spheroid immersed in a D-dimensional Euclidean space. It is noted that the parameter a which is the measure of spheroidicity of the space–time plays here an important role in determining the equation of state of the matter content in such a star. One obtains a realistic solution when the parameter a picks up values [Formula: see text] for D<9 and [Formula: see text] for space–time dimensions D≥9. It is also observed that the higher dimensional space–time accommodates a more massive compact object for a given size compared to that in the usual four dimensional space–times.


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