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Related papers: Anisotropic Stars II : Stability

200 papers

Alternative gravity theory is currently an incredibly significant technique for addressing some enduring experimental difficulties, such as the universe's dark region. They may also be employed in celestial cosmology, producing results that…

General Relativity and Quantum Cosmology · Physics 2024-05-01 Tayyaba Naz , Adnan Malik , Zenab Ramay

In this paper, we consider the mimetic gravitational theory to derive a novel category of anisotropic star models. To end and to put the resulting differential equations into a closed system, the form of the metric potential $g_{rr}$ as…

General Relativity and Quantum Cosmology · Physics 2021-10-11 G. G. L. Nashed

In this paper, we have continued the work of Herrera \emph{et al.} \cite{herrera2012dynamical} in $f(G)$ gravitational theory. For this purpose, a spherically symmetric fluid exhibiting locally anisotropic pressure along with the energy…

General Relativity and Quantum Cosmology · Physics 2020-05-19 M. Z. Bhatti , Z. Yousaf , A. Khadim

The purpose of this paper is to obtain exact solutions for charged anisotropic spherically symmetric matter configuration. For this purpose, we consider known solution for isotropic spherical system in the presence of electromagnetic field…

General Relativity and Quantum Cosmology · Physics 2018-07-04 M. Sharif , Sobia Sadiq

We obtain bounds on the stability of various self-gravitating astrophysical objects using a new measure of shape complexity known as configurational entropy. We apply the method to Newtonian polytropes, neutron stars with an…

General Relativity and Quantum Cosmology · Physics 2016-07-06 Marcelo Gleiser , Nan Jiang

We present a general solution of the Einstein gravitational field equations for the static spherically symmetric gravitational interior spacetime of an isotropic fluid sphere. The solution is obtained by transforming the pressure isotropy…

General Relativity and Quantum Cosmology · Physics 2015-06-17 M. K. Mak , T. Harko

Compact objects have an intrinsic anisotropy due to the presence of strong magnetic fields that cause considerable modifications on the equations of state (EoS). In this work, we study the impact of this anisotropy in the size and shape of…

General Relativity and Quantum Cosmology · Physics 2020-02-05 S. López Pérez , D. Manreza Paret , G. Quintero Angulo , A. Pérez Martínez , D. Alvear Terrero

This paper is devoted to evaluating exact anisotropic spherical solutions for static self-gravitating systems through extended geometric deformation decoupling technique. For this purpose, we consider an isotropic Tolman IV solution and…

General Relativity and Quantum Cosmology · Physics 2020-04-22 M. Sharif , Qanitah Ama-Tul-Mughani

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

We find an exact solution for the stability limit of relativistic charged spheres for the case of constant gravitational mass density and constant charge density. We argue that this provides an absolute stability limit for any relativistic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alessandro Giuliani , Tony Rothman

We examine the possibility of the extra dimensional radius stabilization with only the gravity multiplet in the bulk and some couplings at orbifold fixed points in a supersymmetric Randall-Sundrum model. Unfortunately, we find that the…

High Energy Physics - Theory · Physics 2007-05-23 Nobuhito Maru , Nobuchika Okada

We present a framework to describe completely general first-order perturbations of static, spatially compact, and locally rotationally symmetric class II spacetimes within the theory of general relativity. The perturbation variables are by…

General Relativity and Quantum Cosmology · Physics 2024-05-10 Paulo Luz , Sante Carloni

Within the framework of Einstein's General Relativity we study strange quark stars assuming an interacting equation-of-state. Taking into account the presence of anisotropies in a sphere made of ultra dense matter, we employ the formalism…

General Relativity and Quantum Cosmology · Physics 2023-03-09 Angel Rincon , Grigoris Panotopoulos , Ilidio Lopes

In this paper, we have analyzed the stability of cylindrically symmetric collapsing object filled with locally anisotropic fluid in $f(R,T)$ theory, where $R$ is the scalar curvature and $T$ is the trace of stress-energy tensor of matter.…

General Physics · Physics 2018-11-15 M. Zubair , Hina Azmat , Ifra Noureen

We make precise the heretofore ambiguous statement that anisotropic stress is a sign of a modification of gravity. We show that in cosmological solutions of very general classes of models extending gravity --- all scalar-tensor theories…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Ippocratis D. Saltas , Ignacy Sawicki , Luca Amendola , Martin Kunz

We consider static neutron stars within the framework of $R^2$ gravity. The neutron fluid is described by three different types of realistic equations of state (soft, moderately stiff, and stiff). Using the observational data on the neutron…

General Relativity and Quantum Cosmology · Physics 2018-06-08 Vladimir Folomeev

Within $R^2$ gravity, we study the linear stability of strongly gravitating spherically symmetric configurations supported by a polytropic fluid. All calculations are carried out in the Jordan frame. It is demonstrated that, as in general…

General Relativity and Quantum Cosmology · Physics 2020-09-29 Vladimir Dzhunushaliev , Vladimir Folomeev

We develop a simple model for a self-gravitating spherically symmetric relativistic star which begins to collapse from an initially static configuration by dissipating energy in the form of radial heat flow. We utilize the model to show how…

General Relativity and Quantum Cosmology · Physics 2013-12-10 Ranjan Sharma , Shyam Das

We study the stability of the isotropic vacuum Friedmann universe in gravity theories with higher-order curvature terms of the form $(R_{ab}R^{ab})^{n}$ added to the Einstein-Hilbert Lagrangian of general relativity on approach to an…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jonathan Middleton , John D. Barrow

This study explores the structural formation of various spherically symmetric anisotropic stars within the framework of Rastall theory. To achieve this, we derive modified field equations which are then resolved using the Finch-Skea ansatz,…

General Relativity and Quantum Cosmology · Physics 2025-06-05 Malick Sallah , M. Sharif