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Related papers: A Vaidya-type spacetime with no singularities

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The field equations for static EGBM gravity are obtained and transformed to an equivalent form through a coordinate redefinition. A form for one of the metric potentials that generalises the spheroidal ansatz of Vaidya--Tikekar superdense…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Sudan Hansraj

Static black holes in the conformal anomaly-sourced semi-classical General Relativity in four dimensions were extended to rotating, stationary solutions, recently. These quantum-corrected black holes show different features compared to the…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Metin Gurses , Bayram Tekin

We investigate the geodesic motions of a massive particle and light ray in the hyperplane orthogonal to the symmetry axis in the 5-dimensional hypercylindrical spacetime. The class of the solutions depends on one constant a which is the…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Bogeun Gwak , Bum-Hoon Lee , Wonwoo Lee

In this note a time dependent spacetime is explored in the background of $f(R,T)$ gravity via the gravitational collapse of a massive star. The star is modelled by the Vaidya spacetime which is time dependent in nature. The coupling of…

General Relativity and Quantum Cosmology · Physics 2020-06-02 Prabir Rudra

Following a previous idea, a curved geometry is proposed as being valid in accelerated systems, in Minkowski space. The curvature turns out to be generated by the source of the accelerated motion. An exponential factor depending on $\rho$…

General Physics · Physics 2022-06-15 Hristu Culetu

Several uniqueness results for non-compact complete stationary spacelike surfaces in an $n(\geq 3)$-dimensional Generalized Robertson Walker spacetime are obtained. In order to do that, we assume a natural inequality involving the Gauss…

Differential Geometry · Mathematics 2021-09-08 Danilo Ferreira , Eraldo A. Lima , Alfonso Romero

An anisotropic fluid with variable energy density and negative pressure is proposed, both outside and inside stars. The gravitational field is constant everywhere in free space (if we neglect the local contributions) and its value is of the…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Hristu Culetu

We study the geodesic motion of test particles in the space-time of non-compact boson stars. These objects are made of a self-interacting scalar field and -- depending on the scalar field's mass -- can be as dense as neutron stars or even…

General Relativity and Quantum Cosmology · Physics 2013-08-21 Valeria Diemer , Keno Eilers , Betti Hartmann , Isabell Schaffer , Catalin Toma

The vacuum expectation value of the stress-energy tensor $\left\langle 0\left| T_{\mu\nu} \right|0\right\rangle$ is calculated in several multiply connected flat spacetimes for a massive scalar field with arbitrary curvature coupling. We…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Tsunefumi Tanaka , William A. Hiscock

We construct the disk sources matched to the exact vacuum Kerr and to the two classes of Tomimatsu-Sato spacetimes. We analyze two models of the matter forming these disks. At each radius we consider either a rotating massive ring with…

General Relativity and Quantum Cosmology · Physics 2019-04-17 Tomáš Ledvinka , Jiří Bičák

We reconsider the virial theorem in the presence of a positive cosmological constant Lambda. Assuming steady state, we derive an inequality of the form rho >= A (Lambda / 4 pi GN) for the mean density rho of the astrophysical object. With a…

Astrophysics · Physics 2009-11-06 Marek Nowakowski , Juan Carlos Sanabria , Alejandro Garcia

Dimensional scales are examined in an extended 3+1 Vaidya atmosphere surrounding a Schwarzschild source. At one scale, the Vaidya null fluid vanishes and the spacetime contains only a single spherical 2-surface. Both of these behaviors can…

General Relativity and Quantum Cosmology · Physics 2015-06-25 E. N. Glass , J. P. Krisch

We investigate, in the framework of (2+1) dimensional gravity, stationary, rotationally symmetric gravitational sources of the perfect fluid type, embedded in a space of arbitrary cosmological constant. We show that the matching conditions…

General Relativity and Quantum Cosmology · Physics 2009-10-31 M. Lubo , M. Rooman , Ph. Spindel

The non-equilibrium densities of nonlocal mass-energy are self-governed by kinetic stresses toward quasi-equilibrium sub-configurations. System energy integral of continuous matter-extension coordinates its adaptive densities on each…

General Physics · Physics 2021-05-06 Igor E. Bulyzhenkov

A formulation of classical electrodynamics on an energy-momentum background of constant, non-zero curvature is given. The procedure consists of taking the formulation of standard electrodynamics in the energy-momentum representation, and…

General Physics · Physics 2020-01-01 Boris Ivetić

It is generally believed that any quantum theory of gravity should have a generic feature --- a quantum of length. We provide a physical ansatz to obtain an effective non-local metric tensor starting from the standard metric tensor such…

General Relativity and Quantum Cosmology · Physics 2016-04-08 T. Padmanabhan , Sumanta Chakraborty , Dawood Kothawala

We obtain fields of a relativistic radiating star of non-static mass in the framework of higher dimensional spacetime. Assuming energy-momentum tensor in Higher dimensions analogous to that considered by Vaidya in 4 dimensions we obtain…

Astrophysics · Physics 2007-08-07 B. C. Paul , P. K. Chattopadhyay

Wightman function, the vacuum expectation values of the field squared and the energy-momentum tensor are investigated for a scalar field with general curvature coupling parameter in the geometry of a plate in the de Sitter spacetime. Robin…

High Energy Physics - Theory · Physics 2009-10-08 A. A. Saharian , T. A. Vardanyan

A transitional layer matching the asymptotically flat exterior of a charged, massive toroidal body to an interior with spatially cylindrical symmetry is described. The changes in the geometry, which by themselves would require an energy…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Andrew J. Janca

Including Vaidya metric into the model of Expansive Nondecelerative Universe allows to localize the energy of gravitational field. A term of effective gravitational range is introduced and classic Newton potential is substituted for…

General Physics · Physics 2016-09-22 Julius Vanko , Miroslav Sukenik , Jozef Sima