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Related papers: Modeling usual and unusual anisotropic spheres

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We establish a new algorithm that generates a new solution to the Einstein field equations, with an anisotropic matter distribution, from a seed isotropic solution. The new solution is expressed in terms of integrals of an isotropic…

General Relativity and Quantum Cosmology · Physics 2014-11-17 M. Chaisi , S. D. Maharaj

We compute the equilibrium, the fundamental eigenfrequency of oscillations modes, and quadrupolar tidal deformability of anisotropic polytropic spheres. These studies are respectively performed through the numerical solution of the…

General Relativity and Quantum Cosmology · Physics 2022-01-19 José D. V. Arbañil , Grigoris Panotopoulos

In this paper, we develop two anisotropic solutions for static self-gravitating spherical structure in the presence of electromagnetic field through gravitational decoupling approach in $f(G,T)$ theory, where $G$ and $T$ denote the…

General Relativity and Quantum Cosmology · Physics 2022-11-04 M. Sharif , Komal Hassan

A new four-parameters family of constitutive functions for spherically symmetric elastic bodies is introduced which extends the two-parameters class of polytropic fluid models widely used in several applications of fluid mechanics. The four…

Analysis of PDEs · Mathematics 2022-11-30 Simone Calogero

General relativistic anisotropic fluid models whose fluid flow lines form a shear-free, irrotational, geodesic timelike congruence are examined. These models are of Petrov type D, and are assumed to have zero heat flux and an anisotropic…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Des J. Mc Manus , Alan A. Coley

A, recently presented, general procedure to find static and axially symmetric, interior solutions to the Einstein equations, is extended to the stationary case, and applied to find an interior solution for the Kerr metric. The solution,…

General Relativity and Quantum Cosmology · Physics 2017-01-10 J. L. Hernandez-Pastora , L. Herrera

We study superdense relativistic stars with anisotropic matter distributions with spheroidal spatial hypersurfaces. We propose a methodology to make an anisotropic generalization of the Vaidya-Tikekar superdense star model. The anisotropic…

General Relativity and Quantum Cosmology · Physics 2020-06-23 S. Thirukkanesh , Ranjan Sharma , Sunil D. Maharaj

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 set up in detail the general formalism to model polytropic general relativistic stars with anisotropic pressure. We shall consider two different possible polytropic equations, all of which yield the same Lane-Emden equation in the…

General Relativity and Quantum Cosmology · Physics 2015-06-17 L. Herrera , W. Barreto

In this article, we propose a physical condition to extend interior isotropic solutions to anisotropic domains by gravitational decoupling in the framework of the Minimal Geometric Deformation approach. In particular, it is found that by…

General Relativity and Quantum Cosmology · Physics 2020-03-24 Gabriel Abellán , Angel Rincon , Ernesto Fuenmayor , Ernesto Contreras

We derive the equations of motion for a system undergoing boost-invariant longitudinal and azimuthally-symmetric transverse "Gubser flow" using leading-order anisotropic hydrodynamics. This is accomplished by assuming that the one-particle…

Nuclear Theory · Physics 2015-02-05 Mohammad Nopoush , Radoslaw Ryblewski , Michael Strickland

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

This paper aims to explore a class of static stellar equilibrium configuration of relativistic charged spheres made of a charged perfect fluid. Solving the Einstein-Maxwell field equations, we consider a particularized metric potential,…

General Relativity and Quantum Cosmology · Physics 2021-05-11 J. Kumar , S. K. Maurya , A. K. Prasad , Ayan Banerjee

Lane Emden differential equation of the polytropic gas sphere could be used to construct simple models of stellar structures, star clusters and many configurations in astrophysics. This differential equation suffers from the singularity at…

Solar and Stellar Astrophysics · Physics 2020-03-25 E. A. -B. Abd-Elsalam , Mohamed I. Nouh

Considering the standard "static" spherically symmetric ansatz ds2 = -B(r) dt2 + A(r) dr2 + r2 dOmega2 for Einstein's Equations with perfect fluid source, we ask how we can interpret solutions where A(r) and B(r) are not positive, as they…

General Relativity and Quantum Cosmology · Physics 2010-03-01 Ibrahim Semiz

We model anisotropic neutron stars using three distinct prescriptions for pressure anisotropy, the Horvat, Bowers-Liang, and Covariant models, and three equations of state with different particle compositions, each described by a piecewise…

General Relativity and Quantum Cosmology · Physics 2025-12-24 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo , J. F. Rodriguez

In this work, we have adopted gravitational decoupling by Minimal Geometric Deformation (MGD) approach and have developed an anisotropic version of well-known Tolman VII isotropic solution in the framework of $f(R, T)$ gravity, where $R$ is…

General Relativity and Quantum Cosmology · Physics 2021-06-17 Hina Azmat , M. Zubair

In this investigation, we present a singularity free interior solution of the Einstein field equation for a class of anisotropic compact objects in dimensions $D\geq4$. In accordance with the concept of Vaidya and Tikekar, the geometry of…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Koushik Ballav Goswami , Debadri Bhattacharjee , Anirban Saha , Pradip Kumar Chattopadhyay

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 M. K. Mak , T. Harko

We study the general properties of fluid spheres satisfying the heuristic assumption that their areas and proper radius are equal (the Euclidean condition). Dissipative and non-dissipative models are considered. In the latter case, all…

General Relativity and Quantum Cosmology · Physics 2014-11-20 L. Herrera , N. O. Santos