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Related papers: Conformally flat polytropes for anisotropic matter

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A spherically symmetric collapsing scalar field model is discussed with a dissipative fluid which includes a heat flux. This vastly general matter distribution is analyzed at the expense of a high degree of symmetry in the space-time, that…

General Relativity and Quantum Cosmology · Physics 2017-01-17 Narayan Banerjee , Soumya Chakrabarti

In this paper, we study a family of two-component anisotropic polytropes which model a wide range of spherically symmetric astrophysical systems such as early-type baryonic galaxies. This family is found to contain a large class of models…

General Relativity and Quantum Cosmology · Physics 2013-12-09 Phuc H. Nguyen , Manasvi Lingam

The Einstein-Maxwell equations with anisotropic pressures and electromagnetic field are studied with a polytropic equation of state. New exact solutions to the field equations are generated in terms of elementary functions. Special cases of…

General Relativity and Quantum Cosmology · Physics 2015-06-17 P. Mafa Takisa , S. D. Maharaj

In this paper, the spacetime geometry of Finch and Skea [Class. Quantum Grav., 6 (1989) 467] has been utilized to obtain closed-form solutions for a spherically symmetric anisotropic matter distribution. By examining its physical…

General Physics · Physics 2017-11-23 Ranjan Sharma , Shyam Das , S. Thirukkanesh

We present a new 3D SPH code which solves the general relativistic field + hydrodynamics equations in the conformally flat approximation. Several test cases are considered to test different aspects of the code. We finally apply then the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Roland Oechslin , Stephan Rosswog , Friederich-Karl Thielemann

We give the necessary and sufficient (local) conditions for a metric tensor to be a non conformally flat spherically symmetric solution. These conditions exclusively involve explicit concomitants of the Riemann tensor. As a direct…

General Relativity and Quantum Cosmology · Physics 2012-04-19 Joan Josep Ferrando , Juan Antonio Sáez

We present an anisotropic cosmological model based on a new exact solution of Einstein equations. The matter content consists of an anisotropic scalar field minimally coupled to gravity and of two isotropic perfect fluids that represent…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Saulo Carneiro , Guillermo A. Mena Marugan

Static solutions of white dwarfs with spherical symmetry and local anisotropy are studied in the post-Newtonian approximation. It is argued that the condition for equilibrium must be that the total energy is a minimum for given baryon…

General Relativity and Quantum Cosmology · Physics 2009-10-30 E. S. Corchero

We study spherically symmetric spacetimes for matter distributions with isotropic pressures. We generate new exact solutions to the Einstein field equations which also contains isotropic pressures. We develop an algorithm that produces a…

General Relativity and Quantum Cosmology · Physics 2014-12-23 S. Ngubelanga , S. D. Maharaj

The algebraic properties of drift-flux two-phase fluids models without gravitational and wall friction forces are studied. More precisely, for the two fluids we consider equation of states of polytropic gases. We perform a classification…

Fluid Dynamics · Physics 2021-06-14 Andronikos Paliathanasis

A family of spherically symmetric solutions in the model with 1-component anisotropic fluid is considered. The metric of the solution depends on a parameter q > 0 relating radial pressure and the density and contains n -1 parameters…

General Relativity and Quantum Cosmology · Physics 2007-05-23 H. Dehnen , V. D. Ivashchuk , V. N. Melnikov

We establish that equally-spaced smectic configurations enjoy an infinite-dimensional conformal symmetry and show that there is a natural map between them and null hypersurfaces in maximally-symmetric spacetimes. By choosing the appropriate…

Soft Condensed Matter · Physics 2012-05-14 Gareth P. Alexander , Randall D. Kamien , Ricardo A. Mosna

A physicaly reasonable interpretation is provided for the perfect fluid, sphericaly symmetric, conformally flat ``Stephani Universes''. The free parameters of this class of exact solutions are determined so that the ideal gas relation $p=n…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Roberto A. Sussman

We address the problem of finding static and spherically symmetric anisotropic compact stars in general relativity that admit conformal motions. The study is framed in the language of f(R) gravity theory in order to expose opportunity for…

General Relativity and Quantum Cosmology · Physics 2017-07-06 Ayan Banerjee , Sumita Banerjee , Sudan Hansraj , Ali Ovgun

A family of potential-density pairs that represent spherical shells with finite thickness is obtained from the superposition of spheres with finite radii. Other families of shells with infinite thickness with a central hole are obtained by…

General Relativity and Quantum Cosmology · Physics 2010-11-01 D. Vogt , P. S. Letelier

We construct a model of a universe filled with a perfect fluid with isotropic particle pressure. The anisotropic plane symmetric Kasner spacetime is used as a seed metric and through a conformal mapping a perfect fluid is generated. The…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Sudan Hansraj , Megandhren Govender , Narenee Mewalal

We consider conditions for existence of fermionic quasiparticles in a strongly anisotropic quasi-one-dimensional metal. The adopted model is a model of chains of spin-1/2 Luttinger liquid coupled by small interchain hopping. It is shown…

Condensed Matter · Physics 2008-02-03 A. M. Tsvelik

We analyse spacetimes with a conformal scalar field source, a cosmological constant and a quartic self-interaction term for the scalar field. We also consider additional matter contents in the form of Maxwell and Yang-Mills fields or…

General Relativity and Quantum Cosmology · Physics 2013-12-10 Christian Lübbe

We apply the second-order Israel-Stewart theory of relativistic fluid- and thermodynamics to a physically realistic model of a radiative fluid in a simple anisotropic cosmological background. We investigate the asymptotic future of the…

General Relativity and Quantum Cosmology · Physics 2016-05-10 Dmitry Shogin , Per Amund Amundsen

The possibility of obtaining an open set of regular cosmological models is discussed. Cylindrical stiff perfect fluid cosmologies are studied in detail. The condition for geodesic completeness is easy to check. A large family of…

General Relativity and Quantum Cosmology · Physics 2009-04-10 L. Fernández-Jambrina , L. M. González-Romero