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Related papers: Anisotropic Stars II : Stability

200 papers

We investigate a compact spherically symmetric relativistic body with anisotropic particle pressure profiles. The distribution possesses characteristics relevant to modeling compact stars within the framework of general relativity. For this…

General Relativity and Quantum Cosmology · Physics 2018-02-28 S. K. Maurya , Ayan Banerjee , Sudan Hansraj

We present our study of stability of differentially rotating, axisymmetric neutron stars described by a polytropic equation of state with $\Gamma = 2$. We focus on quasi-toroidal solutions with a degree of differential rotation $\widetilde…

High Energy Astrophysical Phenomena · Physics 2024-02-29 Paweł Szewczyk , Dorota Gondek-Rosińska , Pablo Cerdá-Durán

In this paper we study anisotropic spherical polytropes within the framework of general relativity. Using the anisotropic Tolman-Oppenheimer-Volkov (TOV) equations, we explore the relativistic anisotropic Lane-Emden equations. We find how…

General Relativity and Quantum Cosmology · Physics 2016-07-20 F. Shojai , M. Kohandel , A. Stepanian

We compute the equilibrium, the fundamental eigenfrequency of oscillations modes, and quadrupolar tidal deformability of anisotropic polytropic spheres. These studies are respectively performed through the numerical solution of the…

General Relativity and Quantum Cosmology · Physics 2022-01-19 José D. V. Arbañil , Grigoris Panotopoulos

We model anisotropic neutron stars using three distinct prescriptions for pressure anisotropy, the Horvat, Bowers-Liang, and Covariant models, and three equations of state with different particle compositions, each described by a piecewise…

General Relativity and Quantum Cosmology · Physics 2025-12-24 L. M. Becerra , E. A. Becerra-Vergara , F. D. Lora-Clavijo , J. F. Rodriguez

We extract new classes of anisotropic solutions in the framework of mimetic gravity, by applying the Tolman-Finch-Skea metric and a specific anisotropy not directly depending on it, and by matching smoothly the interior anisotropic solution…

General Relativity and Quantum Cosmology · Physics 2023-04-19 G. G. L. Nashed , Emmanuel N. Saridakis

Interior structures of stellar objects might have small pressure anisotropy due to several reasons, including rotation and the presence of magnetic fields. Here, retaining the approximation of spherical symmetry, we study the possible role…

Solar and Stellar Astrophysics · Physics 2019-11-06 Shaswata Chowdhury , Tapobrata Sarkar

We study the stability of neutron stars with toroidal magnetic fields by magnetohydrodynamic simulation in full general relativity under assumption of axial symmetry. Nonrotating and rigidly rotating neutron stars are prepared for a variety…

Astrophysics · Physics 2008-12-18 Kenta Kiuchi , Masaru Shibata , Shijun Yoshida

We present a new system of equations that fully characterizes adiabatic, radial perturbations of perfect fluid stars within the theory of general relativity. The properties of the system are discussed, and, provided that the equilibrium…

General Relativity and Quantum Cosmology · Physics 2024-05-14 Paulo Luz , Sante Carloni

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

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

Neutron star asteroseismology offers a unique opportunity to probe nuclear physics through stellar oscillations. Although the pressure inside of a neutron star is typically assumed to be isotropic, pressure anisotropy can arise from various…

General Relativity and Quantum Cosmology · Physics 2026-01-13 Jihao Yu , Victor Guedes , Shu Yan Lau , Siddarth Ajith , Kent Yagi

Neutron stars may exhibit pressure anisotropy arising from various physical mechanisms, such as elasticity, magnetic fields, viscosity, and superfluidity. We compute the tidal deformability and the $f$-mode oscillation frequency of…

High Energy Astrophysical Phenomena · Physics 2026-02-17 Victor Guedes , Siddarth Ajith , Shu Yan Lau , Kent Yagi

Radial stability of the continuous pressure gravastar is studied using the conventional Chandrasekhar method. The equation of state for the static gravastar solutions is derived and Einstein equations for small perturbations around the…

General Relativity and Quantum Cosmology · Physics 2012-09-26 Dubravko Horvat , Sasa Ilijic , Anja Marunovic

We construct dark energy stars with Chaplygin-type equation of state (EoS) in the presence of anisotropic pressure within the framework of Einstein gravity. From the classification established by Iyer et al. [Class. Quantum Grav. 2, 219…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Juan M. Z. Pretel

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 analyzes the anisotropic stellar evolution governed by a polytropic equation of state in the framework of $f(R,T,Q)$ gravity, where $Q=R_{ab}T^{ab}$. We construct the field equations, hydrostatic equilibrium equation and trace…

General Relativity and Quantum Cosmology · Physics 2019-02-19 M. Sharif , Arfa Waseem

Perturbations of rotating relativistic stars can be classified by their behavior under parity. For axial perturbations (r-modes), initial data with negative canonical energy is found with angular dependence $e^{im\phi}$ for all values of…

General Relativity and Quantum Cosmology · Physics 2009-10-30 John L. Friedman , Sharon M. Morsink

In the present work, we study the radial and non-radial perturbative stability of neutron stars in which the matter is disformally coupled to the metric. First, we derive the gravitational and the fluid equations of the neutron star in a…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Hamza Boumaza

We construct magnetized stars composed of a fluid stably stratified by entropy gradients in the framework of general relativity, assuming ideal magnetohydrodynamics and employing a barotropic equation of state. We first revisit basic…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Shijun Yoshida , Kenta Kiuchi , Masaru Shibata