Results 21 to 30 of about 63,236 (296)

A bouncing cosmology from VECROs

European Physical Journal C: Particles and Fields, 2023
We argue that, in the same way that in a black hole space-time VECROs will form in order to cancel the gravitational effects of a collapsing mass shell and prevent the formation of a singularity, in a contracting universe a gas of VECROs will form to ...
Robert Brandenberger, Gabrielle A. Mitchell   +1 more
doaj   +1 more source

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
doaj   +1 more source

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
doaj   +1 more source

Gravitational Radiation from a Naked Singularity -- Odd-Parity Perturbation -- [PDF]

, 1999
It has been suggested that a naked singularity may be a good candidate for a strong gravitational wave burster. The naked singularity occurs in the generic collapse of an inhomogeneous dust ball.
Chandrasekhar, H. Iguchi, K.-i. Nakao, T. Harada, Tolman   +4 more
core   +2 more sources

Gravitational Waves around a Naked Singularity -- Odd-Parity Perturbation of Lemaitre-Tolman-Bondi Space-Time -- [PDF]

, 1998
The motion of a spherical dust cloud is described by the Lemaitre-Tolman-Bondi solution and is completely specified by initial values of distributions of the rest mass density and specific energy of the dust fluid.
A. Ori, B. Waugh, C. W. Misner, C. W. Misner, D. Christodoulou, D. M. Eardley, D. S. Goldwirth, E. Seidel, E. Seidel, H. Bondi, Hideo Iguchi, I. H. Dwivedi, I. H. Dwivedi, I. H. Dwivedi, J. M. Bardeen, Ken-ichi Nakao, P. S. Joshi, P. S. Joshi, P. S. Joshi, R. C. Tolman, R. P. C. A. Newman, R. Penrose, R. Penrose, R. Penrose, S. Jhingan, S. L. Shapiro, S. L. Shapiro, S. W. Hawking, S. W. Hawking, T. P. Singh, T. Regge, Tomohiro Harada, U. H. Gerlach   +32 more
core   +2 more sources

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
doaj   +1 more source

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, Chandrasekhar, H. Iguchi, Hawking, Hawking, K.-I. Nakao, T. Harada, Tolman   +7 more
core   +3 more sources

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, Divya Tahelyani, Ashok B. Joshi, Dipanjan Dey, Pankaj S. Joshi   +4 more
doaj   +1 more source

Quantum evaporation of a naked singularity [PDF]

, 2005
We investigate here quantum effects in gravitational collapse of a scalar field model which classically leads to a naked singularity. We show that non-perturbative semi-classical modifications near the singularity, based on loop quantum gravity, give ...
A. Ashtekar, A. Krolak, D. Chistodoulou, D. Chistodoulou, P. S. Joshi, Pankaj S. Joshi, Parampreet Singh, R. Penrose, Rituparno Goswami   +8 more
core   +3 more sources

Quantum backreaction on chronology horizons

Journal of High Energy Physics, 2022
We extend in two directions our recent investigation of strongly interacting quantum fields in a class of spacetimes with chronology horizons (Misner spacetimes).
Roberto Emparan, Marija Tomašević
doaj   +1 more source