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Singularity resolution in gravitational collapse
Physical Review D, 2022 We investigate the unhindered gravitational collapse of a homogeneous scalar field with nonzero potential, a two-dimensional analog of the Mexican hat-shaped Higgs field potential. The collapsing scalar field is surrounded by an exterior retarded (outgoing) generalized Vaidya spacetime. We prove that the density dependence on the scale factor cannot be
Karim Mosani +3 more
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ON THE SOLUTION TO THE "FROZEN STAR" PARADOX, NATURE OF ASTROPHYSICAL BLACK HOLES, NON-EXISTENCE OF GRAVITATIONAL SINGULARITY IN THE PHYSICAL UNIVERSE AND APPLICABILITY OF THE BIRKHOFF'S THEOREM [PDF]
, 2010 Oppenheimer and Snyder found in 1939 that gravitational collapse in vacuum produces a "frozen star", i.e. the collapsing matter only asymptotically approaches the gravitational radius (event horizon) of the mass, but never cross it within a finite time ...
Shuang-Nan Zhang
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The singularities of gravitational collapse and cosmology [PDF]
Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences, 1970 A new theorem on space-time singularities is presented which largely incorporates and generalizes the previously known results. The theorem implies that space-time singularities are to be expected if either the universe is spatially closed or there is an ‘object’ undergoing relativistic ...
Stephen W. Hawking, Roger Penrose
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Gravitationally collapsing stars in f(R) gravity
European Physical Journal C: Particles and Fields, 2021 The gravitational dynamics of a collapsing matter configuration which is simultaneously radiating heat flux is studied in f(R) gravity. Three particular functional forms in f(R) gravity are considered to show that it is possible to envisage boundary ...
Suresh C. Jaryal, Ayan Chatterjee
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Averaged energy conditions for vector fields
Physics Letters B, 2023 In this work we shall obtain sufficient conditions for the appearance of singularities in gravitational theories which propagate an extra vector degree of freedom, based on the known relaxations of the singularity theorems.
Francisco José Maldonado Torralba
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Environment and Planning B Urban Analytics and City Science, 2021 We propose an upgraded gravitational model which provides population counts beyond the binary (urban/non-urban) city simulations. Numerically studying the model output, we find that the radial population density gradients follow power-laws where the ...
Yunfei Li, D. Rybski, J. Kropp
semanticscholar +1 more source
Exact gravitational plane waves and two-dimensional gravity
Physics Letters B, 2018 We discuss dynamical aspects of gravitational plane waves in Einstein theory with massless scalar fields. The general analytic solution describes colliding gravitational waves with constant polarization, which interact with scalar waves and, for generic ...
Jorge G. Russo
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Physical Processes in Naked Singularity Formation [PDF]
, 2002 Gravitational collapse is one of the most fruitful subjects in gravitational physics. It is well known that singularity formation is inevitable in complete gravitational collapse. It was conjectured that such a singularity should be hidden by horizons if
Chandrasekhar +7 more
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Light trajectory and shadow shape in the rotating naked singularity
European Physical Journal C: Particles and Fields, 2022 In this paper, we investigate the light trajectories and shadow properties in the rotating version of null naked singularity (NNS) spacetime which is derived using the Newman–Janis algorithm without complexification method.
Vishva Patel +4 more
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Nature of Singularities in Gravitational Collapse [PDF]
Progress of Theoretical Physics Supplement, 1999 We discuss several aspects of cosmic censorship hypothesis. There is evidence both in favor and against the hypothesis. On one hand one can prove that cosmic censorship holds in several special cases and on the other hand there is a number of special solutions of Einstein equations in which it is violated.
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