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Related papers: Static, spherically symmetric objects in Type-II m…

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In the spherically symmetric case the requirements of regularity of density and pressures and finiteness of the ADM mass $m$, together with the weak energy condition, define the family of asymptotically flat globally regular solutions to…

High Energy Physics - Theory · Physics 2007-05-23 Irina Dymnikova

This paper investigates a spherically symmetric compact relativistic body with isotropic pressure profiles within the framework of general relativity. In order to solve the Einstein's field equations, we have considered the Vaidya-Tikekar…

Astrophysics of Galaxies · Physics 2021-11-29 Jitendra Kumar , Puja Bharti

The main objective of this paper is to investigate the impact of $f(\mathcal{Q},\mathcal{T})$ gravity on the geometry of anisotropic compact stellar objects, where $\mathcal{Q}$ is non-metricity and $\mathcal{T}$ is the trace of the…

General Relativity and Quantum Cosmology · Physics 2024-02-21 M. Zeeshan Gul , M. Sharif , Adeeba Arooj

In this article, a special static spherically symmetric perfect fluid solution of Einstein's equations is provided. Though pressure and density both diverge at the origin, their ratio remains constant. The solution presented here fails to…

General Physics · Physics 2009-09-29 F. Rahaman , M. Kalam , S. Chakraborty , K. Maity , B. Raychaudhuri

The trace-free Einstein equations contain one equation less than the complete field equations. In a static and spherically symmetric spacetime, the number of field equations is thus reduced to two. The equation of pressure isotropy of…

General Relativity and Quantum Cosmology · Physics 2024-03-27 Sudan Hansraj , Chevarra Hansraj , Njabulo Mkhize , Abdelghani Errehymy , Christian G. Boehmer

For a static, perfect fluid sphere with a general equation of state, we obtain the relativistic equation of hydrostatic equilibrium, namely the Tolman-Oppenheimer-Volkov equation, as the thermodynamical equilibrium in the microcanonical, as…

General Relativity and Quantum Cosmology · Physics 2013-05-14 Zacharias Roupas

In this paper, the gravitational field equations for static spherically symmetric perfect fluid models with a polytropic equation of state, $p=k\rho^{1+1/n}$, are recast into two complementary 3-dimensional {\it regular} systems of ordinary…

General Relativity and Quantum Cosmology · Physics 2009-10-31 U. S. Nilsson , C. Uggla

We utilize a recent formulation of a spherically symmetric spacetime endowed with a general decomposition of the energy momentum tensor [Phys. Rev. D, 75, 024031 (2007)] to derive equations governing spherically symmetric distributions of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Paul Lasky , Anthony Lun

We have investigated spherically symmetric spacetimes which contain a perfect fluid obeying the polytropic equation of state and admit a kinematic self-similar vector of the second kind which is neither parallel nor orthogonal to the fluid…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Hideki Maeda , Tomohiro Harada , Hideo Iguchi , Naoya Okuyama

f(Q) gravity is the extension of symmetric teleparallel general relativity (STGR), in which both curvature and torsion vanish, and gravity is attributed to nonmetricity. This work performs theoretical analyses of static and spherically…

General Relativity and Quantum Cosmology · Physics 2022-02-10 Wenyi Wang , Hua Chen , Taishi Katsuragawa

We construct the general spherically symmetric and self-similar solution of the Einstein-Vlasov system (collisionless matter coupled to general relativity) with massless particles, under certain regularity conditions. Such solutions have a…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Jose M. Martin-Garcia , Carsten Gundlach

We generalize the Tolman-Oppenheimer-Volkoff equations for space-times endowed with a Weyssenhoff like torsion field in the Einstein-Cartan theory. The new set of structure equations clearly show how the presence of torsion affects the…

General Relativity and Quantum Cosmology · Physics 2019-10-18 Paulo Luz , Sante Carloni

Cylindrically symmetric stationary spacetimes are examined in the framework of string-inpired generalized theory of gravity. In four dimensions this theory contains a dilatonic scalar field in addition to gravity. A charged perfect fluid…

General Relativity and Quantum Cosmology · Physics 2007-05-23 P. Klepac

The NGT field equations with sources are expanded first about a flat Minkowski background and then about a GR background to first-order in the antisymmetric part of the fundamental tensor, $g_{\mu\nu}$. From the general, static spherically…

General Relativity and Quantum Cosmology · Physics 2008-02-03 J. W. Moffat

We study spherically symmetric solutions to the Einstein-Euler equations which model an idealized relativistic neutron star surrounded by vacuum. These are barotropic fluids with a free boundary, governed by an equation of state which sets…

Analysis of PDEs · Mathematics 2021-08-16 Grigorios Fournodavlos , Volker Schlue

Solutions of Einstein vacuum equations, for a static pseudospherically symmetric system, are presented. They describe a naked singularity and a singular solution with many resemblances to the Schwartzschild solution but with two major…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Luis A. Anchordoqui , Graciela S. Birman , Jose D. Edelstein , Carlos Núñez

Six exact solutions are obtained in the general scalar-tensor theory of gravity related to spatially homogeneous wave-like models of the Universe. Wave-like space-time models allow the existence of privileged coordinate systems where the…

General Relativity and Quantum Cosmology · Physics 2020-10-06 K. Osetrin , A. Filippov , E. Osetrin

Utilizing various gauges of the radial coordinate we give a description of static spherically symmetric space-times with point singularity at the center and vacuum outside the singularity. We show that in general relativity (GR) there exist…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Plamen Fiziev

In the present article we find a new class of solutions of Einstein's field equations. It describes stationary, cylindrically symmetric spacetimes with closed timelike geodesics everywhere outside the symmetry axis. These spacetimes contain…

General Relativity and Quantum Cosmology · Physics 2010-04-20 Oyvind Gron , Steinar Johannesen

Spherically symmetric equilibrium configurations of perfect fluid obeying a polytropic equation of state are studied in spacetimes with a repulsive cosmological constant. The configurations are specified in terms of three parameters---the…

General Relativity and Quantum Cosmology · Physics 2016-11-17 Zdeněk Stuchlík , Stanislav Hledík , Jan Novotný