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Related papers: Dilation Dark Matter in Vaidya-De-Sitter Spacetime

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Considering Vaidya-Tikekar metric, we obtain a class of solutions of the Einstein-Maxwell equations for a charged static fluid sphere. The physical 3-space (t=constant) here is described by pseudo-spheroidal geometry. The relativistic…

Solar and Stellar Astrophysics · Physics 2015-06-05 Pradip Kr. Chattopadhyay , Rumi Deb , Bikash Chandra Paul

A radiatively stable de Sitter spacetime is constructed by considering an intrinsically non-commutative and generalized-geometric formulation of string theory, which is related to a family of F-theory models endowed with non-trivial…

High Energy Physics - Theory · Physics 2020-01-07 Per Berglund , Tristan Hübsch , Djordje Minic

We obtain a new class of solutions by revisiting the Vaidya-Tikekar stellar model in the linear regime. Making use of the Vaidya and Tikekar metric ansatz [J. Astrophys. Astron. {\bf3} (1982) 325] describing the spacetime of static…

General Relativity and Quantum Cosmology · Physics 2020-07-01 Ranjan Sharma , Shyam Das , Megan Govender , Dishant M. Pandya

The dynamical consequences of a bimetric scalar-tensor theory of gravity with a dynamical light speed are investigated in a cosmological setting. The model consists of a minimally-coupled self-gravitating scalar field coupled to ordinary…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. A. Clayton , J. W. Moffat

We model a compact radiant star that undergoes gravitational collapse from a certain initial static configuration until it becomes a black hole. The star consists of a fluid with anisotropy in pressures, bulk viscosity, in addition to the…

General Relativity and Quantum Cosmology · Physics 2023-04-26 A. C. Mesquita , M. F. A. da Silva

The spacetimes for Vaidya's radiating stellar exterior and Kinnersley's photon rocket in a cosmological background are obtained by performing the same conformal transformation as is used to obtain the Robertson-Walker metric from Minkowski…

General Relativity and Quantum Cosmology · Physics 2008-09-22 M. L. McClure , Kaem Anderson , Kirk Bardahl

The condensed matter analogs are useful for consideration of the phenomena related to the quantum vacuum. This is because in condensed matter we know physics both in the infrared and in the ultraviolet limits, while in particle physics and…

General Relativity and Quantum Cosmology · Physics 2025-11-11 G. E. Volovik

We consider a spherically symmetric stellar model in general relativity whose interior consists of a pressureless fluid undergoing microscopic velocity diffusion in a cosmological scalar field. We show that the diffusion dynamics compel the…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Artur Alho , Simone Calogero

We consider homothetic maps in a family of spherical relativistic star models. A generalization of Vaidya's radiating metric provides a fluid atmosphere of radiation and strings. The similarity structure of the string fluid is investigated.

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

We propose a simple model in which the cosmological dark matter consists of particles whose mass increases with the scale factor of the universe. The particle mass is generated by the expectation value of a scalar field which does not have…

Astrophysics · Physics 2016-10-26 Greg W. Anderson , Sean M. Carroll

As a generalization of the Schwarzschild solution, Vaidya presented a radiating metric to develop a model of the exterior of a star including its radiation field, called Vaidya metric. The present paper deals with the investigation on the…

Differential Geometry · Mathematics 2019-05-08 Absos Ali Shaikh , Haradhan Kundu , Jayshree Sen

We prove a theorem that characterizes a large family of non-static solutions to Einstein equations in $N$-dimensional space-time, representing, in general, spherically symmetric Type II fluid. It is shown that the best known Vaidya-based…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. G. Ghosh , A. K. Dawood

Some properties of an exact solution due to Vaidya, describing the gravitational field produced by a point particle in the background of the static Einstein universe are examined. The maximal analytic extension and the nature of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. Astefanesei , E. Radu

We study relativistic stars in the scale-dependent scenario, which is one of the approaches to quantum gravity, and where Newton's constant is promoted to a scale-dependent quantity. First, the generalized structure equations are derived…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Grigoris Panotopoulos , Ángel Rincón , Ilídio Lopes

A non-static solution of Einstein's field equations of General Relativity representing the gravitational field of an axisymmetric radiation flow is obtained using the Eddington or the Kerr-Schild form for the metric. A solution obtained…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sanjay M. Wagh , Pradeep S. Muktibodh

Taking the flat rotation curve as input and treating the matter content in the galactic halo region as perfect fluid, we obtain space time metric at the galactic halo region in the framework of general relativity. We find that the resultant…

General Relativity and Quantum Cosmology · Physics 2010-11-26 F. Rahaman , K. K. Nandi , A. Bhadra , M. Kalam , K. Chakraborty

Stars can be treated as self-gravitating fluid. Krori and Barua (1975) gave an analytical solutions to that kind of fluids. In this connection, we propose a de-Sitter model for an anisotropic strange star with the Krori-Barua spacetime. We…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Mehedi Kalam , Farook Rahaman , Saibal Ray , Sk. Monowar Hossein , Indrani Karar , Jayanta Naskar

We construct models of static, spherically symmetric shells supported by the radiation flux of a luminous neutron star in the Schwarzschild metric. The atmospheres are disconnected from the star and levitate above its surface. Gas pressure…

High Energy Astrophysical Phenomena · Physics 2016-04-05 Maciek Wielgus , Aleksander Sadowski , Wlodek Kluzniak , Marek Abramowicz , Ramesh Narayan

We consider a relativistic radiating spherical star in conformally flat spacetimes. In particular we study the junction condition relating the radial pressure to the heat flux at the boundary of the star which is a nonlinear partial…

General Relativity and Quantum Cosmology · Physics 2014-12-23 G. Abebe , K. S. Govinder , S. D. Maharaj

We investigate the cosmological dynamics of a universe described by Lyra's geometry in the presence of dark energy (DE) and dark matter (DM). Dark energy is modeled as a quintessence scalar field with bulk viscosity, while dark matter is…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-20 Giridhari Deogharia , Madhurima Pandey , Ashadul Halder