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Related papers: Modeling usual and unusual anisotropic spheres

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Relativistic, spherically symmetric configurations consisting of a gravitating magnetized anisotropic fluid are studied. For such configurations, we obtain static equilibrium solutions with an axisymmetric, poloidal magnetic field produced…

General Relativity and Quantum Cosmology · Physics 2015-03-03 Vladimir Folomeev , Vladimir Dzhunushaliev

We study the dynamical instability of a spherically symmetric anisotropic fluid which collapses adiabatically under the condition of vanishing expansion scalar. The Newtonian and post Newtonian regimes are considered in detail. It is shown…

General Relativity and Quantum Cosmology · Physics 2012-04-18 L. Herrera , G. Le Denmat , N. O. Santos

We study the Einstein equations of the static spherically symmetric anisotropic fluid system in curvature coordinates to find algorithms that generate all solutions and all solutions that are regular at the center. All possible combinations…

General Relativity and Quantum Cosmology · Physics 2021-09-01 M M Akbar , R Solanki

A general procedure to find static and axially symmetric, interior solutions to the Einstein equations is presented. All the so obtained solutions, verify the energy conditions for a wide range of values of the parameters, and match…

General Relativity and Quantum Cosmology · Physics 2016-11-07 J. L. Hernandez-Pastora , L. Herrera , J. Martin

Adding linear combinations $R^2,R_{\mu\nu}R^{\mu\nu}$ and $R_{\mu\nu\eta\delta}R^{\mu\nu\eta\delta}$ with Einstein-Hilbert action we obtain interior metric of an an-isotropic spherically symmetric collapsing (ASSC) stellar cloud. We assume…

General Physics · Physics 2015-12-14 Hossein Ghaffarnejad

In this paper, we consider the mimetic gravitational theory to derive a novel category of anisotropic star models. To end and to put the resulting differential equations into a closed system, the form of the metric potential $g_{rr}$ as…

General Relativity and Quantum Cosmology · Physics 2021-10-11 G. G. L. Nashed

In this paper we study anisotropic spherical polytropes within the framework of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov (TOV) equations, we explore the relativistic anisotropic Lane-Emden equations. We find how…

General Relativity and Quantum Cosmology · Physics 2016-07-20 F. Shojai , M. Kohandel , A. Stepanian

In this paper, we develop a new relativistic compact stellar model for a spherically symmetric anisotropic matter distribution. The model has been obtained through generating a new class of solutions by invoking the Tolman {\em ansatz} for…

General Relativity and Quantum Cosmology · Physics 2020-11-25 Piyali Bhar , Shyam Das , Bikram Keshari Parida

We study exact solutions of the Einstein-Maxwell equations for the interior gravitational field of static spherically symmetric charged compact spheres. The spheres consist of an anisotropic fluid with a charge distribution that gives rise…

General Relativity and Quantum Cosmology · Physics 2022-02-18 Krsna Dev

The truncated Israel-Stewart theory of irreversible thermodynamics is used to describe the bulk viscous pressure and the anisotropic stress in a class of spatially homogeneous viscous fluid cosmological models. The governing system of…

General Relativity and Quantum Cosmology · Physics 2010-04-06 R. J. van den Hoogen , A. A. Coley

In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein's general theory of relativity. The Einstein's field equations have been solved by…

General Relativity and Quantum Cosmology · Physics 2021-06-23 Piyali Bhar , Pramit Rej , P. Mafa Takisa , M. Zubair

Ivanov pointed out substantial analytical difficulties associated with self-gravitating, static, isotropic fluid spheres when pressure explicitly depends on matter density. Simplification achieved with the introduction of electric charge…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Victor Varela , Farook Rahaman , Saibal Ray , Koushik Chakraborty , Mehedi Kalam

By a choice of new variables the pressure isotropy condition for spherically symmetric static perfect fluid spacetimes can be made a quadratic algebraic equation in one of the two functions appearing in it. Using the other variable as a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gyula Fodor

We provide all basic equations and concepts required to carry out a general study on axially symmetric static sources. The Einstein equations and the conservation equations are written down for a general anisotropic static fluid endowed…

General Relativity and Quantum Cosmology · Physics 2015-06-12 L. Herrera , A. Di Prisco , J. Ibañez , J. Ospino

The Standard Cosmological Model assumes that the Universe is, on average, homogeneous and isotropic for large scales (z>1), but this principle has been questioned from the results about Cosmic Microwave Background. This radiation has…

General Physics · Physics 2016-04-19 Ericsson López , Mario Llerena , Franklin Aldás

We consider static charged fluid spheres with a cosmological constant. We assume a polytropic equation of state, $p \propto \rho^\Gamma$, and a power law charge distribution, $q\propto r^n$. Using this, we convert the generalised…

General Relativity and Quantum Cosmology · Physics 2026-03-30 Alex Stornelli , Anish Agashe

Rotation is ubiquitous in the Universe, and recent kinematic surveys have shown that early type galaxies and globular clusters are no exception. Yet the linear response of spheroidal rotating stellar systems has seldom been studied. This…

Astrophysics of Galaxies · Physics 2019-05-15 Simon Rozier , Jean-Baptiste Fouvry , Philip G. Breen , Anna Lisa Varri , Christophe Pichon , Douglas C. Heggie

The manifesto of the current article is to investigate the compact anisotropic matter profiles in the context of one of the modified gravitational theories, known as $f(\mathcal{R}, \mathcal{T})$ gravity, where $\mathcal{R}$ is a Ricci…

General Relativity and Quantum Cosmology · Physics 2021-01-05 G. Mustafa , Xia Tie-Cheng , Mushtaq Ahmad , M. Farasat Shamir

Unique features of particle orbits produce novel signatures of gravitational observable phenomena, and are quite useful in testing compact astrophysical objects in general relativity or modified theories of gravity. Here we observe a…

General Relativity and Quantum Cosmology · Physics 2023-10-24 Shao-Wen Wei , Yu-Peng Zhang , Yu-Xiao Liu , Robert B. Mann

We present a class of exact solutions of Einstein field equations for a shear-free spherically symmetric anisotropic fluid undergoing radial heat flow. The interior metric fulfilled all the relevant physical and thermodynamic conditions and…

General Relativity and Quantum Cosmology · Physics 2016-01-21 B. C. Tewari , Kali Charan
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