Results 151 to 160 of about 681 (164)

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
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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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Introducing Spacetime Singularities and Acausalities

1995
Abstract This book is simultaneously an essay in the philosophy of science and the foundations of physics. It seeks to assess the implications of spacetime singularities and acausal features of relativistic spacetimes for the general theory of relativity and the philosophy of space and time.
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Conformal Quantisation in Singular Spacetimes

1986
It is generally accepted now that any reasonable classical theory of gravitation must admit spacetime singularities where the curvatures would grow unbounded and the usual laws of physics may breakdown (see e.g. Geroch, 1979 or Penrose, 1979). Within the classical framework, the physical universe is modelled by a spacetime manifold on which the matter ...
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