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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 this paper we are concerned with the effects of anisotropic pressure on the boundary conditions of anisotropic Lane-Emden equation and homology theorem. Some new exact solutions of this equation are derived. Then some of the theorems…

General Relativity and Quantum Cosmology · Physics 2015-07-10 F. Shojai , M. R. Fazel , A. Estepanian , M. Kohandel

Recently, Khadekar (2007) presented the solutions with uniform energy density for anisotropic spheres in bimetric theory. We present here a general analytic solution to the field equations in bimetric theory for anisotropic fluids for a…

General Physics · Physics 2011-09-26 Naveen Bijalwan

In this work we study class I interior solutions supported by anisotropic polytropes. The generalized Lane--Emden equation compatible with the embedding condition is obtained and solved for a different set of parameters in both the…

General Relativity and Quantum Cosmology · Physics 2021-03-10 A. Ramos , C. Arias , E. Fuenmayor , E. Contreras

We show that it is possible to obtain credible static anisotropic spherically symmetric matter configurations starting from known density profiles and satisfying a nonlocal equation of state. These particular types of equation of state…

General Relativity and Quantum Cosmology · Physics 2015-06-25 H. Hernandez , L. A. Nunez

The fluid models mentioned in the title are studied in a modified approach, based on two formulas for the mass function. All characteristics of the fluid are expressed through a master potential, satisfying an ordinary second order…

General Relativity and Quantum Cosmology · Physics 2011-04-21 B. V. Ivanov

In this paper, the gravitational field equations for static spherically symmetric perfect fluid models with a polytropic equation of state, $p=k\rho^{1+1/n}$, are recast into two complementary 3-dimensional {\it regular} systems of ordinary…

General Relativity and Quantum Cosmology · Physics 2009-10-31 U. S. Nilsson , C. Uggla

Spherically symmetric equilibrium configurations of perfect fluid obeying a polytropic equation of state are studied in spacetimes with a repulsive cosmological constant. The configurations are specified in terms of three parameters---the…

General Relativity and Quantum Cosmology · Physics 2016-11-17 Zdeněk Stuchlík , Stanislav Hledík , Jan Novotný

This work is concerned with the finiteness problem for static, spherically symmetric perfect fluids in both Newtonian Gravity and General Relativity. We derive criteria on the barotropic equation of state guaranteeing that the corresponding…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. Mark Heinzle

We consider the general situation of a compact relativistic body with anisotropic pressures in the presence of the electromagnetic field. The equation of state for the matter distribution is linear and may be applied to strange stars with…

General Relativity and Quantum Cosmology · Physics 2009-01-16 S. Thirukkanesh , S. D. Maharaj

In this paper, we have introduced new viable solutions of Einstein-Maxwell field equations by incorporating the features of anisotropic matter distribution in the realm of General theory of Relativity ($GR$). For this procurement, we have…

General Relativity and Quantum Cosmology · Physics 2023-03-29 H. Nazar , M. Azam , G. Abbas , R. Ahmed , R. Naeem

We propose a new model which describes relativistic hydrodynamics and generalizes the standard Euler system of isentropic perfect fluids. Remarkably, our system admits a convex extension which allows us to transform it to a symmetric…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Robert Beig , Philippe G. LeFloch

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 fluid models mentioned in the title are classified. All characteristics of the fluid are expressed through a master potential, satisfying an ordinary second order differential equation. Different constraints are imposed on this core of…

General Relativity and Quantum Cosmology · Physics 2015-05-27 B. V. Ivanov

The Lagrangian description of fluid flow in relativistic cosmology is extended to the case of flow accelerated by pressure. In the description, the entropy and the vorticity are obtained exactly for the barotropic equation of state. In…

Astrophysics · Physics 2009-10-31 Hideki Asada

We set up the general formalism to model polytropic Newtonian stars with anisotropic pressure. We obtain the corresponding Lane-Emden equation. A heuristic model based on an ansatz to obtain anisotropic matter solutions from known solutions…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 L. Herrera , W. Barreto

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 compare Newtonian and general relativistic descriptions of the stationary accretion of self-gravitating fluids onto compact bodies. Spherical symmetry and thin gas approximation are assumed. Luminosity depends, amongst other factors, on…

General Relativity and Quantum Cosmology · Physics 2010-12-24 Edward Malec , Tomasz Rembiasz

In this work, a spherically symmetric and static relativistic anisotropic fluid sphere solution of the Einstein field equations is provided. To build this particular model, we have imposed metric potential $e^{2\lambda(r)}$ and an equation…

General Relativity and Quantum Cosmology · Physics 2020-05-25 Francisco Tello-Ortiz , M. Malaver , Angel Rincon , Y. Gomez-Leyton

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