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Related papers: $C^3$ matching conditions for anisotropic fluids

200 papers

In this talk we show a stiff fluid solution of the Einstein equations for a cylindrically symmetric spacetime. The main features of this metric are that it is non-separable in comoving coordinates for the congruence of the worldlineS of the…

General Relativity and Quantum Cosmology · Physics 2009-06-01 L. Fernández-Jambrina

We study Born-Infeld gravity coupled to an anisotropic fluid in a static, spherically symmetric background. The free function characterizing the fluid is selected on the following grounds: i) recovery of the Reissner-Nordstr\"om solution of…

General Relativity and Quantum Cosmology · Physics 2017-11-22 C. Menchon , Gonzalo J. Olmo , D. Rubiera-Garcia

We show that a flow (timelike congruence) in any type $B_{1}$ warped product spacetime is uniquely and algorithmically determined by the condition of zero flux. (Though restricted, these spaces include many cases of interest.) The flow is…

General Relativity and Quantum Cosmology · Physics 2011-02-01 Mustapha Ishak , Kayll Lake

We consider static neutron stars within the framework of $R^2$ gravity. The neutron fluid is described by three different types of realistic equations of state (soft, moderately stiff, and stiff). Using the observational data on the neutron…

General Relativity and Quantum Cosmology · Physics 2018-06-08 Vladimir Folomeev

In a recent series of papers new exact analytical solutions of the Einstein equations representing interior spacetimes sourced by stationary rigidly rotating cylinders of different kinds of fluids have been displayed, [Phys. Rev. D {\bf…

General Relativity and Quantum Cosmology · Physics 2023-12-18 Marie-Noëlle Célérier

A nonsingular localized static classical solution is constructed for standard Einstein gravity coupled to an $SO(3)\times SO(3)$ chiral model of scalars (Skyrme model). This solution corresponds to a spacetime defect and its construction…

General Relativity and Quantum Cosmology · Physics 2015-06-15 F. R. Klinkhamer , C. Rahmede

The condition for pressure isotropy is reduced to a recurrence equation with variable, rational coefficients of order three. We prove that this difference equation can be solved in general. Consequently we can find an exact solution to the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 A. J. John , S. D. Maharaj

Instead of conformal to flat spacetime, we take the metric conformal to a spacetime which can be thought of as ``minimally'' curved in the sense that free particles experience no gravitational force yet it has non-zero curvature. The base…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Naresh Dadhich

We classify the self-similar solutions to a class of Weingarten curvature flow of connected compact convex hypersurfaces, isometrically immersed into space forms with non-positive curvature, and obtain a new characterization of a sphere in…

Differential Geometry · Mathematics 2009-05-07 Guanghan Li , Isabel Salavessa , Chuanxi Wu

We apply the 1+1+2 covariant semi-tetrad approach to describe a general static and spherically symmetric relativistic stellar object which contains two fluids with anisotropic pressure. The corresponding Tolman-Oppenheimer-Volkoff equations…

General Relativity and Quantum Cosmology · Physics 2023-01-04 Nolene F. Naidu , Sante Carloni , Peter Dunsby

We investigate the equations of anisotropic axisymmetric incompressible viscous fluids in the exterior of a cylinder of $\R^3$, rotating around an inhomogeneous vector $B(t, r)$. We prove uniform local existence with respect to the Rossby…

Analysis of PDEs · Mathematics 2008-12-15 Olfa Bejaoui

This work is devoted to the study of non-Newtonian fluids of grade three on two-dimensional and three-dimensional bounded domains, driven by a nonlinear multiplicative Wiener noise. More precisely, we establish the existence and uniqueness…

Probability · Mathematics 2024-02-27 Yassine Tahraoui , Fernanda Cipriano

We consider dynamics of a flat anisotropic Universe filled by a perfect fluid near a cosmological singularity in quadratic gravity. Two possible regimes are described -- the Kasner anisotropic solution and an isotropic "vacuum radiation"…

General Relativity and Quantum Cosmology · Physics 2017-01-04 A. Toporensky , D. Müller

We investigate how a spherically symmetric fluid modifies the Schwarzschild vacuum solution when there is no exchange of energy-momentum between the fluid and the central source of the Schwarzschild metric. This system is described by means…

General Relativity and Quantum Cosmology · Physics 2018-11-26 J Ovalle , R Casadio , R da Rocha , A Sotomayor , Z Stuchlik

We consider plane-symmetric spacetimes satisfying Einstein's field equations with positive cosmological constant, when the matter is a fluid whose pressure is equal to its mass-energy density (i.e. a so-called stiff fluid). We study the…

General Relativity and Quantum Cosmology · Physics 2012-05-01 Philippe G. LeFloch , Sophonie B. Tchapnda

We introduce a new type of generating theorems in General Relativity for anisotropic, static, spherically symmetric solutions of the Einstein field equations. The results are used to derive a class of solutions that can serve as new models…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Paulo Luz , Sante Carloni

This paper is the first in a sequence of three devoted to the formulation of a theory of self-gravitating anisotropic fluids in both Newtonian and relativistic gravity. In this first paper we set the stage, place our work in the context of…

General Relativity and Quantum Cosmology · Physics 2024-06-06 Tom Cadogan , Eric Poisson

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

General Relativity and Quantum Cosmology · Physics 2016-04-29 David Sloan

A new class of solutions describing analytical solutions for compact stellar structures has been developed within the tenets of General Relativity. Considering the inherent anisotropy in compact stars, a stable and causal model for…

General Relativity and Quantum Cosmology · Physics 2021-10-14 Jay Solanki , Bhashin Thakore

We consider a broad class of static, spherically symmetric generalized Schwarzschild-like solutions with multiple non-interacting anisotropic fluid sources and derive the coordinate transformation from Schwarzschild-like (curvature) to…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Zeyu Zeng , Elena Kopteva