Results 171 to 180 of about 35,096 (197)

No more spacetime singularities?

General Relativity and Gravitation, 1994
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Kostelecký, V. Alan, Perry, Malcolm
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On singularity-free spacetimes

Pramana, 1995
We consider here the metric for the singularity-free family of fluid models. The metric is unique for cylindrically symmetric space-time with metric potentials being separable functions of radial and time coordinates in the comoving coordinates. It turns out that fluid models separate out into two classes, withρ ≠µp in general butρ = 3p in particular ...
Naresh Dadhich, L K Patel, R Tikekar
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Strengths of singularities in Vaidya spacetimes

Physical Review D, 1987
The strengths of shell-focusing singularities in the ingoing Vaidya spacetimes are examined in terms of limiting focusing conditions. The singularities are found to be strong-curvature singularities only for mass functions which are initially linear functions of the advanced time.
, Rajagopal, , Lake
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First Singular Homology Group of Spacetime

Reports on Mathematical Physics, 2019
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Agrawal, Gunjan, Pathak, Roma
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Tolerance for spacetime singularities

Foundations of Physics, 1996
A common reaction to the Penrose-Hawking singularity theorems is that Einstein's general theory of relativity contains the seeds of its own destruction. This attitude is critically examined. A more tolerant attitude toward spacetime singularities is recommended.
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Singularities in closed spacetimes

Classical and Quantum Gravity, 1985
The existence of singularities in closed universes is discussed without making any causality assumptions. It is argued that there must be singularities in closed universes in which the past null cones of points on some compact slice reconverge. This singularity can be localised to the past of the slice if a reconvergence condition on time-like ...
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Singularities in self-similar spacetimes

Classical and Quantum Gravity, 1986
Similarity vector fields on general Lorentzian manifolds are studied. Incompleteness of certain similarity orbits is applied to establish a singularity theorem for general relativistic self-similar perfect fluids. The authors acknowledge that some of the mathematical background also can be found in the book ''Foundations of differential geometry.
Collins, C. B., Lang, J. M.
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Singularities in Cosmological Spacetimes

2014
Theorems state that gravitational collapse from generic but non-singular initial conditions results in some type of singular behavior. Here the nature of the resultant approach to the singularity is examined in spatially homogeneous, anisotropic, vacuum cosmological spacetimes .
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Singularities in spacetimes with torsion

International Journal of Theoretical Physics, 1990
The author briefly comments on the question of whether or not the Hawking-Penrose singularity theorems are affected by the introduction of torsion. To that end, the corresponding generalization of the Raychaudhuri equation is considered. The paper, however, chiefly consists in proposals of what should be done in future work.
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Singularities in conformally flat spacetimes

Physics Letters A, 1977
Abstract It is shown that the energy density must diverge at least as fast as 1/t along certain null geodesics near a strong curvature singularity in any conformally flat spacetime.
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