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The hydrodynamic evolution of self-gravitating gaseous stars is governed by the Euler-Poisson equations. We study the structure of the linear approximation of barotropic perturbations around spherically symmetric equilibria based on…

Analysis of PDEs · Mathematics 2020-05-15 Juhi Jang , Tetu Makino

It is shown that exact spherically symmetric solutions to Einstein's Field Equations exist such that, over an open region of the spacetime, they are singularity free, satisfy the dominant energy condition, represent elastic matter with a…

General Relativity and Quantum Cosmology · Physics 2020-08-05 Irene Brito , J. Carot , E. G. L. R. Vaz

One of the most common assumptions has been made that the pressure inside the star is isotropic in nature. However, the pressure is locally anisotropic in nature which is a more realistic case. In this study, we investigate certain…

General Relativity and Quantum Cosmology · Physics 2022-11-18 H. C. Das

We propose two models for constant density relativistic perfect-fluid spheres supported by thin shell configurations. These models are obtained from the Schwarzschild constant density star solution: the first via the collapse of the…

General Relativity and Quantum Cosmology · Physics 2020-09-16 João Luís Rosa , Pedro Piçarra

There is introduced a class of barotropic equations of state (EOS) which become polytropic of index $n = 5$ at low pressure. One then studies asymptotically flat solutions of the static Einstein equations coupled to perfect fluids having…

General Relativity and Quantum Cosmology · Physics 2009-10-31 R. Beig , M. Karadi

Dense cores inherit turbulent motions from the interstellar medium in which they form. As a tool for comparison to both simulations and observations, it is valuable to construct theoretical core models that can relate their internal density…

Astrophysics of Galaxies · Physics 2025-06-05 Sanghyuk Moon , Eve C. Ostriker

Quasi-local variables, i.e. quantities whose values can be derived from physics accessible within an arbitrarily small neighborhood of a spacetime point, are used to construct the equation of state (EoS) for the anisotropic fluid in the…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Dubravko Horvat , Sasa Ilijic , Anja Marunovic

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 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

We consider a gravitating spherically symmetric configuration consisting of a scalar field non-minimally coupled to ordinary matter in the form of a perfect fluid. For this system we find static, regular, asymptotically flat solutions for…

Solar and Stellar Astrophysics · Physics 2013-05-29 V. Dzhunushaliev , V. Folomeev , D. Singleton

Spacetimes with a thin shell offer a framework where both the dynamical stability and the thermodynamical stability of the matter comprising the shell can be consistently studied. In the present work, we consider the dynamical and…

General Relativity and Quantum Cosmology · Physics 2026-05-25 Ernesto Eiroa , Griselda Figueroa-Aguirre , Miguel Peñafiel

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

Spherical systems with polytropic equations of state are of great interest in astrophysics. They are widely used to describe neutron stars, red giants, white dwarfs, brown dwarfs, main sequence stars, galactic halos, and globular clusters…

General Relativity and Quantum Cosmology · Physics 2013-09-24 P. H. Nguyen , J. F. Pedraza

In general relativity static gaseous atmospheres may be in hydrostatic balance in the absence of a supporting stellar surface, provided that the luminosity is close to the Eddington value. We construct analytic models of optically thin,…

High Energy Astrophysical Phenomena · Physics 2016-01-11 M. Wielgus , W. Kluźniak , A. Sądowski , R. Narayan , M. Abramowicz

The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mustapha Ishak , Kayll Lake

We study the stability of thin-shell wormholes in Einstein-Maxwell-Gauss-Bonnet gravity. The equation of state of the thin shell wormhole is considered first to obey a generalized Chaplygin gas and then we generalize it to an arbitrary…

General Relativity and Quantum Cosmology · Physics 2013-12-10 Z. Amirabi , M. Halilsoy , S. Habib Mazharimousavi

We study some properties of static spherically symmetric elastic bodies in general relativity using both analytical and numerical tools. The materials considered belong to the class of John elastic materials and reduce to perfect fluids…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Håkan Andréasson , Simone Calogero

The paper is concerned with the Einstein equations for a spherically symmetric static distribution of anisotropic matter. The equations are cast into a system of Fuchsian type ODE for certain scalar invariants of the strain. And then the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Jiseong Park

We explore gravitating relativistic spheres composed of an anisotropic, barotropic uid. We assume a bi-polytropic equation of state which has a linear and a power-law terms. The generalized Tolman-Oppenheimer-Volkoff (TOV) equation which…

General Relativity and Quantum Cosmology · Physics 2016-11-03 Nematollah Riazi , S. Sedigheh Hashemi , S. Naseh Sajadi , S. Shahrokh Assyaee

We present a class of new relativistic solutions with anisotropic fluid for compact stars in hydrostatic equilibrium. The interior space-time geometry considered here for compact objects are described by parameters namely, $\lambda$, $k$,…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Bikash Chandra Paul , Rumi Deb