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Related papers: Static Charged Polytropic Spheres with a Cosmologi…

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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 research paper investigates the impact of non-metricity and matter source on the geometry of charged spheres in the presence of anisotropic matter configuration. We use a specific model of extended symmetric teleparallel theory to…

General Relativity and Quantum Cosmology · Physics 2024-12-03 M. Zeeshan Gul , Faisal Javed , M. Sharif , Shalan Alkarni

We study the static stellar equilibrium configurations ofuncharged and charged spheres composed by a relativistic polytropic fluid, and compare with those of spheres composed by a non-relativistic polytropic fluid, the later case already…

General Relativity and Quantum Cosmology · Physics 2018-05-30 José D. V. Arbañil , Vilson T. Zanchin

The effects of the cosmological constant on the static equilibrium configurations and stability against small radial perturbations of relativistic polytropic spheres are investigated. This study numerically solves the hydrostatic…

General Relativity and Quantum Cosmology · Physics 2020-04-15 José D. V. Arbañil , Pedro H. R. S. Moraes

We demonstrate that in the framework of standard general relativity polytropic spheres with properly fixed polytropic index $n$ and relativistic parameter $\sigma$, giving ratio of the central pressure $p_\mathrm{c}$ to the central energy…

General Relativity and Quantum Cosmology · Physics 2017-03-16 Jan Novotný , Jan Hladík , Zdeněk Stuchlík

The aim of this paper is to discuss the theory of Newtonian and relativistic polytropes with generalized polytropic equation of state. For this purpose, we formulated the general framework to discuss the physical properties of polytrops…

General Physics · Physics 2016-06-22 M. Azam , S. A. Mardan , I. Noreen , M. A. Rehman

Static spherically symmetric anisotropic source has been studied for the Einstein-Maxwell field equations assuming the erstwhile cosmological constant $ \Lambda $ to be a space-variable scalar, viz., $ \Lambda = \Lambda(r) $. Two cases have…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Saibal Ray , Sumana Bhadra , Anand S. Sengupta

We explore a class of compact charged spheres made of a charged perfect fluid with a polytropic equation of state. The charge density is chosen to be proportional to the energy density. The study is performed by solving the…

General Relativity and Quantum Cosmology · Physics 2014-08-11 José D. V. Arbañil , José P. S. Lemos , Vilson T. Zanchin

We complete the stability study of general relativistic spherically symmetric polytropic perfect fluid spheres, concentrating attention to the newly discovered polytropes containing region of trapped null geodesics. We compare the methods…

General Relativity and Quantum Cosmology · Physics 2020-05-14 Jan Hladík , Camilo Posada , Zdeněk Stuchlík

This paper examines the general formalism and applications of isotropic as well as anisotropic polytropic stars in curvature-matter coupled gravity. For this purpose, we consider static spherical and Schwarzschild spacetimes in the interior…

General Relativity and Quantum Cosmology · Physics 2022-02-16 M. Sharif , Amal Majid , M. Shafaqat

In the present paper we analyze and discuss some mathematical aspects of the fluid-static configurations of a self-gravitating perfect gas enclosed in a spherical solid shell. The mathematical model we consider is based on the well-known…

In this paper we investigate gravitationally bound, spherically symmetric equilibrium configurations consisting of ordinary (polytropic) matter nonminimally coupled to an external chameleon scalar field. We show that this system has static,…

Solar and Stellar Astrophysics · Physics 2012-04-03 Vladimir Folomeev , Douglas Singleton

In this paper we study the isotropic cases of static charged fluid spheres in general relativity. For this purpose we consider two different specialization and under these we solve the Einstein-Maxwell field equations in isotropic…

General Relativity and Quantum Cosmology · Physics 2011-08-25 Basanti Das , Pratap Chandra Ray , Irina Radinschi , Farook Rahaman , Saibal Ray

In this work we evaluate the physical acceptability of relativistic anisotropic spheres modeled by two polytropic equations of state -- with the same newtonian limit -- commonly used to describe compact objects in General Relativity. We…

General Relativity and Quantum Cosmology · Physics 2021-02-02 D. Suárez-Urango , L. A. Núñez , H. Hernández

The Tolman VII space-time is one of the few physically acceptable exact solutions in general relativity. In this paper, we derive a generalised Tolman VII solution which includes a charge and a cosmological constant. We analyse the spatial…

General Relativity and Quantum Cosmology · Physics 2025-01-13 James Ripple , Anish Agashe

Static, spherically symmetric solutions representing stars made of barotropic perfect fluid are studied in the context of two theories of type-II minimally modified gravity, VCDM and VCCDM. Both of these theories share the property that no…

General Relativity and Quantum Cosmology · Physics 2022-05-25 Antonio De Felice , Shinji Mukohyama , Masroor C. Pookkillath

Some theorems for a static prefect fluid sphere, i.e. a star, in the presence of a positive cosmological constant are proved. These theorems put bounds on the pressure profile and internal compactness of the star.

General Relativity and Quantum Cosmology · Physics 2014-02-05 F. Shojai , A. Shojai , M. Mousavi

We obtain an equation for the density profile in a self-gravitating polytropic spherically symmetric turbulent fluid with an equation of state $p_{\rm gas}\propto \rho^\Gamma$. This is done in the framework of ensembles of molecular clouds…

Astrophysics of Galaxies · Physics 2021-06-30 S. Donkov , I. Zh. Stefanov , T. V. Veltchev , R. S. Klessen

A spherically symmetric charged ideal fluid solution of Einstein field equation is given in the presence of the cosmological constant and two well known example of this type of solution is presented. If the matter is confined in a region,…

General Relativity and Quantum Cosmology · Physics 2007-11-30 N. Ozdemir

Spherically symmetric static solutions of the Einstein equations with a positive cosmological constant for the energy-momentum tensor of a barotropic perfect fluid are governed by the Tolman-Oppenheimer-Volkoff-de Sitter equation. Existence…

Analysis of PDEs · Mathematics 2016-03-09 Tetu Makino
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