Gravitational collapse in higher-dimensional charged-Vaidya space-time

Pramana ◽  
2003 ◽  
Vol 60 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Kishor D. Patil
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.


2007 ◽  
Vol 40 (4) ◽  
pp. 749-763 ◽  
Author(s):  
Ujjal Debnath ◽  
Narayan Chandra Chakraborty ◽  
Subenoy Chakraborty

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.


1988 ◽  
Vol 03 (08) ◽  
pp. 1959-1979 ◽  
Author(s):  
CHIA-HSIUNG TZE

We present an alternative formulation of Polyakov’s regularization of Gauss’ integral formula for a single closed Feynman path. A key element in his proof of the D=3 fermi-bose transmutations induced by topological gauge fields, this regularization is linked here with the existence and properties of a nontrivial topological invariant for a closed space ribbon. This self-linking coefficient, an integer, is the sum of two differential characteristics of the ribbon, its twisting and writhing numbers. These invariants form the basis for a physical interpretation of our regularization. Their connection to Polyakov’s spinorization is discussed. We further generalize our construction to the self-linking, twisting and writhing of higher dimensional d=n (odd) submanifolds in D=(2n+1) space-time. Our comprehensive analysis intends to supplement Polyakov’s work as it identifies a natural path to its higher dimensional mathematical and physical generalizations. Combining the theorems of White on self-linking of manifolds and of Adams on nontrivial Hopf fibre bundles and the four composition-division algebras, we argue that besides Polyakov’s case where (d, D)=(1, 3) tied to complex numbers, the potentially interesting extensions are two chiral models with (d, D)=(3, 7) and (7, 15) uniquely linked to quaternions and octonions. In Memoriam Richard P. Feynman


1998 ◽  
Vol 13 (38) ◽  
pp. 3069-3072
Author(s):  
L. C. GARCIA DE ANDRADE

Negative energy densities in spinning matter sources of non-Riemannian ultrastatic traversable wormholes require the spin energy density to be higher than the negative pressure or the radial tension. Since the radial tension necessary to support wormholes is higher than the spin density in practice, it seems very unlikely that wormholes supported by torsion may exist in nature. This result corroborates earlier results by Soleng against the construction of the closed time-like curves (CTC) in space–time geometries with spin and torsion. It also agrees with earlier results by Kerlick according to which Einstein–Cartan (EC) gravity torsion sometimes enhance the gravitational collapse instead of avoiding it.


Pramana ◽  
2010 ◽  
Vol 74 (4) ◽  
pp. 513-523 ◽  
Author(s):  
P. K. Chattopadhyay ◽  
B. C. Paul

2012 ◽  
Vol 44 (10) ◽  
pp. 2503-2520 ◽  
Author(s):  
Ranjan Sharma ◽  
Ramesh Tikekar

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