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Related papers: Anisotropic Stars II : Stability

200 papers

The equations describing the adiabatic, small radial oscillations of general relativistic stars are generalized to include the effects of a cosmological constant. The generalized eigenvalue equation for the normal modes is used to study the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 C. G. Boehmer , T. Harko

The problem of the dynamical stability of anistropic systems is studied, by proposing a criterion in terms of the adiabatic local index $\gamma$. The result has general validity and can be applied to several physical situations.…

General Relativity and Quantum Cosmology · Physics 2019-02-14 Giuseppe Alberti , Marco Merafina

The dynamical instability of relativistic polytropic spheres, embedded in a spacetime with a repulsive cosmological constant, is studied in the framework of general relativity. We apply the methods used in our preceding paper to study the…

General Relativity and Quantum Cosmology · Physics 2020-07-22 Camilo Posada , Jan Hladík , Zdenek Stuchlík

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

The study of perturbation of self-gravitating celestial cylindrical object have been carried out in this paper. We have designed a framework to construct the collapse equation by formulating the modified field equations with the background…

General Physics · Physics 2017-11-08 M. Zaeem-ul-Haq Bhatti , Z. Yousaf

We present a spherically symmetric solution of the general relativistic field equations in isotropic coordinates for anisotropic neutral fluid, compatible with a super dense star modeling by considering a specific choice of anisotropy…

General Relativity and Quantum Cosmology · Physics 2014-10-23 Neeraj Pant , Narendra Pradhan , Manuel Malaver

We study the stability of non-relativistic polytropic stars within two modified gravity theories i.e., Beyond Horndeski gravity and Eddington inspired Born Infeld theories using the configuration entropy method. We use spatially localized…

General Relativity and Quantum Cosmology · Physics 2017-12-21 C. Wibisono , A. Sulaksono

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 2017-10-04 T. Harko , M. K. Mak

Spherically symmetric relativistic stars with the polytropic equation of state, which possess the local pressure anisotropy, are considered in the context of general relativity. The modified Lane-Emden equations are derived for the special…

General Relativity and Quantum Cosmology · Physics 2018-01-25 A. A. Isayev

A main question in astrophysics and cosmology has been the severe stability of the astrophysical objects, whether a particular equilibrium configuration is stable. In this article, we study the relativistic self-gravitating, hydrostatic…

General Relativity and Quantum Cosmology · Physics 2022-03-23 A. S. Saad , M. I. Nouh , A. A. Shaker , T. M. Kamel

We study the oscillations and stability of self-gravitating cylindrically symmetric fluid systems and collisionless systems. This is done by studying small perturbations to the equilibrium system and finding the normal modes, using methods…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-15 Patrick C. Breysse , Marc Kamionkowski , Andrew Benson

Anisotropic stresses are ubiquitous in nature, but their modeling in General Relativity is poorly understood and frame dependent. We introduce the first study on the dynamical properties of anisotropic self-gravitating fluids in a covariant…

General Relativity and Quantum Cosmology · Physics 2019-06-05 Guilherme Raposo , Paolo Pani , Miguel Bezares , Carlos Palenzuela , Vitor Cardoso

We complete previous investigations on the thermodynamics of self-gravitating systems by studying the grand canonical, grand microcanonical and isobaric ensembles. We also discuss the stability of polytropic spheres in the light of a…

Astrophysics · Physics 2009-11-07 P. H. Chavanis

We study adiabatic, radial perturbations of static, self-gravitating perfect fluids within the theory of general relativity employing a new perturbative formalism. We show that by considering a radially static observer, the description of…

General Relativity and Quantum Cosmology · Physics 2024-05-20 Paulo Luz , Sante Carloni

We study nonaxisymmetric perturbations of rotating relativistic stars. modeled as perfect-fluid equilibria. Instability to a mode with angular dependence $\exp(im\phi)$ sets in when the frequency of the mode vanishes. The locations of these…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Nikolaos Stergioulas , John L. Friedman

Our manuscript aims to analysis the viability and stability of anisotropic stellar objects in the modified symmetric teleparallel gravity. A particular model of this extended theory is considered to formulate explicit field equations which…

General Relativity and Quantum Cosmology · Physics 2024-08-29 M. Zeeshan Gul , M. Sharif , Adeeba Arooj

The equilibrium configurations of slowly rotating anisotropic self-gravitating fluids are computed using the extended Hartle structure equations, including anisotropic effects, derived in our previous paper. We focus on the so-called…

General Relativity and Quantum Cosmology · Physics 2025-10-20 Philip Beltracchi , Camilo Posada

This work is based on stability analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment in $f(R,T)$ gravity, where $R$ is Ricci scalar and $T$ corresponds to the trace of energy momentum tensor.…

General Physics · Physics 2014-11-26 Ifra Noureen , M. Zubair

In the present paper we consider convection and cracking instabilities as well as their interplay. We develop a simple criterion to identify equations of state unstable to convection, and explore the influence of buoyancy on cracking (or…

General Relativity and Quantum Cosmology · Physics 2018-11-14 Héctor Hernández , Luis A. Núñez , Adriana Vásquez-Ramírez

Some models (such as the Skyrme model, a low-energy effective field theory for QCD) suggest that the high-density matter prevailing in neutron star interiors may be significantly anisotropic. Anisotropy is known to affect the bulk…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Hector O. Silva , Caio F. B. Macedo , Emanuele Berti , Luís C. B. Crispino