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Related papers: Study of polytropes with Generalized polytropic Eq…

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Spherically symmetric relativistic stars with the polytropic equation of state (EoS), which possess the local pressure anisotropy, are considered within the framework of general relativity. The generalized Lane-Emden equations are derived…

General Relativity and Quantum Cosmology · Physics 2018-01-12 A. A. Isayev

We shall consider some common models in linear thermo-elasticity within a common structural framework. Due to the flexibility of the structural perspective we will obtain well-posedness results for a large class of generalized models…

Mathematical Physics · Physics 2016-10-27 Santwana Mukhopadhyay , Rainer Picard , Sascha Trostorff , Marcus Waurick

We argue that an arbitrary general relativistic static anisotropic fluid sphere, (static and spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully mimicked by suitable linear…

General Relativity and Quantum Cosmology · Physics 2017-11-29 Petarpa Boonserm , Tritos Ngampitipan , Matt Visser

We investigate relativistic spherically symmetric static perfect fluid models in the framework of the theory of dynamical systems. The field equations are recast into a regular dynamical system on a 3-dimensional compact state space,…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. Mark Heinzle , N. Rohr , C. Uggla

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

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

We consider the linear equation of state for matter distributions that may be applied to strange stars with quark matter. In our general approach the compact relativistic body allows for anisotropic pressures in the presence of the…

General Relativity and Quantum Cosmology · Physics 2015-05-13 S. D. Maharaj , S. Thirukkanesh

We present a simple, analytic and straightforward method to elucidate the effects produced by polytropic fluids on any other gravitational source, no matter its nature, for static and spherically symmetric spacetimes. As a direct…

General Relativity and Quantum Cosmology · Physics 2022-03-30 J. Ovalle , E. Contreras , Z. Stuchlik

In this paper we will discuss charged stars with polytropic equation of state, where we will try to derive an equation analogous to the Lane-Emden equation. We will assume that these stars are spherically symmetric, and the electric field…

Astrophysics · Physics 2009-11-10 Rodrigo Picanco , Manuel Malheiro , Subharthi Ray

A recently presented method for the study of evolving self-gravitating relativistic spheres is applied to the description of the evolution of relativistic polytropes. Two different definitions of relativistic polytrope, yielding the same…

General Relativity and Quantum Cosmology · Physics 2009-11-10 L. Herrera , W. Barreto

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

In the framework of general relativity, the dynamics of a general barotropic fluid are coupled to the Einstein equations, which govern the structure of the underlying spacetime. We establish a priori estimates and well-posedness in Sobolev…

Analysis of PDEs · Mathematics 2024-10-03 Zeming Hao , Wei Huo , Shuang Miao

In this work, we present a class of relativistic and well-behaved solution to Einstein's field equations for anisotropic matter distribution. We perform our analysis by using the Buchdahl ansatz for the metric function grr. Three different…

General Relativity and Quantum Cosmology · Physics 2022-03-29 Amit Kumar Prasad , Jitendra Kumar

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

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

We provide new exact solutions to the Einstein-Maxwell system of equations which are physically reasonable. The spacetime is static and spherically symmetric with a charged matter distribution. We utilise an equation of state which is…

General Relativity and Quantum Cosmology · Physics 2015-06-12 S. D. Maharaj , P. Mafa Takisa

We discuss the effect that small fluctuations of local anisotropy of pressure, and energy density, may have on the occurrence of cracking in spherical compact objects, satisfying a polytropic equation of state. Two different kind of…

General Relativity and Quantum Cosmology · Physics 2016-02-17 L. Herrera , E. Fuenmayor , P. León

Static spherically symmetric solutions of the Einstein's field equations in isotropic coordinates representing perfect fluid matter distributions from Newtonian potential-density pairs are investigated. The approach is illustrated with…

General Relativity and Quantum Cosmology · Physics 2020-11-24 Gonzalo García-Reyes

In this work, we study self-gravitating objects that obey a polytropic equation of state in hyperbolic symmetry. Specifically, we describe in detail the steps to derive the Lane-Emden equation from the structure equations of the system. To…

General Relativity and Quantum Cosmology · Physics 2025-05-29 M. Carrasco-H , E. Contreras , E. Fuenmayor , P. León

In a previously work, we undertook a static and anisotropic content in $f(T)$ theory and obtained new spherically symmetric solutions considering a constant torsion and some particular conditions for the pressure. In this paper, still in…

General Physics · Physics 2012-02-22 M. Hamani Daouda , Manuel E. Rodrigues , M. J. S. Houndjo