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Related papers: Anisotropic Stars II : Stability

200 papers

In this work, we have investigated anisotropic neutron stars in the framework of Rastall-Rainbow gravity. All our calculations were computed using the IU-FSU realistic equation of state (EoS), in which was considered two cases: standard…

High Energy Astrophysical Phenomena · Physics 2019-11-11 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Cesar V. Flores , Tiago J. N. da Silva , Débora P. Menezes

Within the metric formalism of $f(R)$ theories of gravity, where $R$ is the Ricci scalar, we study the hydrostatic equilibrium structure of compact stars with the inclusion of anisotropic pressure. In particular, we focus on the $f(R)=…

General Relativity and Quantum Cosmology · Physics 2022-07-11 Juan M. Z. Pretel , Sergio B. Duarte

We complete our previous investigation concerning the structure and the stability of "isothermal" spheres in general relativity. This concerns objects that are described by a linear equation of state $P=q\epsilon$ so that the pressure is…

Astrophysics · Physics 2009-11-13 Pierre-Henri Chavanis

We present a covariant and gauge-invariant formulation of the theory of radial adiabatic linear perturbations of self-gravitating, non-dissipative imperfect fluids within the theory of general relativity. By codifying the thermodynamical…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Paulo Luz , Sante Carloni

This paper is devoted to studying charged anisotropic static spherically symmetric solutions through gravitationally decoupled minimal geometric deformation technique in $f(R)$ gravity. For this purpose, we first consider the known…

General Relativity and Quantum Cosmology · Physics 2019-07-24 M. Sharif , Arfa Waseem

Within the framework of $f(R,T)$ theories of gravity, we investigate the hydrostatic equilibrium of anisotropic neutron stars with a physically relevant equation of state (EoS) for the radial pressure. In particular, we focus on the $f(R,T)…

General Relativity and Quantum Cosmology · Physics 2023-01-10 Juan M. Z. Pretel

The main purpose of this paper is to obtain physically stable stellar models coupled with anisotropic matter distribution in the context of $f(\mathcal{R},\mathrm{T}^{2})$ theory. For this, we consider a static spherical geometry and…

General Relativity and Quantum Cosmology · Physics 2024-06-06 Tayyab Naseer , M. Sharif , Sana Manzoor , Arooj Fatima

In this paper, we study the impact of anisotropy on neutron stars with different equations of state, which have been modeled by a piecewise polytropic function with continuous sound speed. Anisotropic pressure in neutron stars is often…

High Energy Astrophysical Phenomena · Physics 2024-01-22 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo

We study the spherically symmetric collapsing star in terms of dynamical instability. We take the framework of extended teleparallel gravity with non-diagonal tetrad, power-law form of model presenting torsion and matter distribution as…

General Relativity and Quantum Cosmology · Physics 2016-03-16 Abdul Jawad , Shamaila Rani

We investigate the conditions for the (in)stability of the isotropic pressure condition in collapsing spherically symmetric, dissipative fluid distributions. It is found that dissipative fluxes, and/or energy density inhomogeneities and/or…

General Relativity and Quantum Cosmology · Physics 2020-05-27 L. Herrera

?In this work, we study the orbital stability of stationary solutions to the relativistic Vlasov-Manev system. This system is a kinetic model describing the evolution of a stellar system subject to its own gravity with some relativistic…

Analysis of PDEs · Mathematics 2013-03-26 Cyril Rigault

In this paper we study the equilibrium configurations of anisotropic self-gravitating fermions, by extending to general relativity the solutions obtained in a previous paper. This treatment also generalizes to anisotropic systems the…

Astrophysics of Galaxies · Physics 2015-07-23 Marco Merafina , Giuseppe Alberti

Globular clusters are dense stellar systems whose core slowly contracts under the effect of self-gravity. The rate of this process was recently found to be directly linked to the initial amount of velocity anisotropy: tangentially…

Astrophysics of Galaxies · Physics 2022-06-01 Kerwann Tep , Jean-Baptiste Fouvry , Christophe Pichon

Based on the Weierstrass representation of second variation we develop a non-spectral theory of stability for isoperimetric problem with minimized and constrained two-dimensional functionals of general type and free endpoints allowed to…

Fluid Dynamics · Physics 2014-03-28 Leonid G. Fel , Boris Y. Rubinstein

In this paper, we extend the Finch-Skea isotropic ansatz representing a self-gravitating interior to two anisotropic spherical solutions within the context of Rastall gravity. For this purpose, we use a newly developed technique, named as…

General Relativity and Quantum Cosmology · Physics 2024-10-03 M. Sharif , M. Sallah

We analyze previous results on the stability of uniformly and differentially rotating, self-gravitating, gaseous and stellar, axisymmetric systems to derive a new stability criterion for the appearance of toroidal, m=2 Intermediate (I) and…

Astrophysics · Physics 2007-09-24 D. M. Christodoulou , I. Shlosman , J. E. Tohline

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

A general formalism developed few years ago to model polytropic Newtonian stars with anisotropic pressure is applied to model stars for which, both, radial and tangential pressure satisfy polytropic equations of state. We obtain the…

General Relativity and Quantum Cosmology · Physics 2020-07-02 G. Abellan , E. Fuenmayor , L. Herrera

This thesis investigates in the time domain a particular class of second order perturbations of a perfect fluid non-rotating compact star: those arising from the coupling between first order radial and non-radial perturbations. This problem…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Andrea Passamonti

In this paper we investigate the gravothermal instability of spherical stellar systems endowed with a radially anisotropic velocity distribution. We focus our attention on the effects of anisotropy on the conditions for the onset of the…

Astrophysics · Physics 2009-10-30 M. Magliocchetti , G. Pucacco , E. Vesperini