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We expand previous work on an inverse approach to Einstein Field Equations where we include fluids with energy flux and consider the vanishing of the anisotropic stress tensor. We consider the approach using warped product spacetimes of…

General Relativity and Quantum Cosmology · Physics 2011-02-01 James Richardson , Mustapha Ishak

In this paper, we consider static spherical structure to develop some anisotropic solutions by employing the extended gravitational decoupling scheme in the background of…

General Relativity and Quantum Cosmology · Physics 2023-02-10 M. Sharif , Tayyab Naseer

We have performed a series of high resolution N-body experiments on a Connection Machine CM-5 in order to study the stability of collisionless self-gravitating spherical systems. We interpret our results in the framework of symplectic…

Astrophysics · Physics 2015-06-24 J. Perez , J-M Alimi , J-J Aly , H. Scholl

In this work a class of interior solution for Einstein field equations corresponding to a spherically symmetric anisotropic fluid sphere has been obtained under the assumption that the cosmological constant is spatially variable. The…

General Relativity and Quantum Cosmology · Physics 2011-03-07 R. N. Tiwari , Saibal Ray

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Jose P. Mimoso , David Wands

This paper explores exact cosmological solutions of anisotropic universe model through Noether symmetry technique in energy-momentum squared gravity. This theory resolves the primordial singularity and provides viable cosmological…

General Relativity and Quantum Cosmology · Physics 2023-05-24 M. Sharif , M. Zeeshan Gul

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

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

We investigate solutions of Einstein field equations for the non-static spherically symmetric perfect fluid case using different equations of state. The properties of an exact spherically symmetric perfect fluid solutions are obtained which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Sharif , T. Iqbal

This article focuses on different anisotropic models within the framework of a specific modified $f(\mathcal{R},\mathcal{T},\mathcal{R}_{\zeta\gamma}\mathcal{T}^{\zeta\gamma})$ gravity theory. The study adopts a static spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Yihu Feng , Tayyab Naseer , G. Mustafa , S. K. Maurya

Following the recent success of anisotropic hydrodynamics we propose a new, general prescription for the hydrodynamics expansion around an anisotropic background. The anisotropic distribution is fixing exactly the complete energy-momentum…

High Energy Physics - Phenomenology · Physics 2016-10-12 Leonardo Tinti

The Einstein-Maxwell (or Einstein) system of field equations plays a substantial role in the modeling of compact stars. Although due to its non-linearity getting an exact solution for the system of field equations is a difficult task, the…

General Relativity and Quantum Cosmology · Physics 2022-01-26 Jitendra Kumar , Puja Bharti

In this paper, we study the physical characteristics of anisotropic spherically symmetric quark star candidates for $R+2\sigma T$ gravity model, where $R$, $\sigma$ and $T$ depict scalar curvature, coupling parameter, and the trace of the…

General Relativity and Quantum Cosmology · Physics 2020-01-08 M. Sharif , Arfa Waseem

This paper is devoted to discuss compact stars in $f(\mathscr{R},\mathscr{G})$ gravity, where $\mathscr{R}$ and $\mathscr{G}$ denote the Ricci scalar and Gauss-Bonnet invariant respectively. To meet this aim, we consider spherically…

General Relativity and Quantum Cosmology · Physics 2020-05-11 G. Mustafa , M. Farasat Shamir , Xia Tie-Cheng

Anisotropic cosmological spacetimes are constructed from spherically symmetric solutions to Einstein's equations coupled to nonlinear electrodynamics and a positive cosmological constant. This is accomplished by finding solutions in which…

High Energy Physics - Theory · Physics 2011-07-19 Dan N. Vollick

In this paper, we give an overview of the results established in [3] which provides the first rigorous derivation of hydrodynamic equations from the Boltzmann equation for inelastic hard spheres in 3D. In particular, we obtain a new system…

Analysis of PDEs · Mathematics 2022-05-04 Ricardo J. Alonso , Bertrand Lods , Isabelle Tristani

An algorithm based on the choice of a single monotone function (subject to boundary conditions) is presented which generates all regular static spherically symmetric perfect fluid solutions of Einstein's equations. For physically relevant…

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

Spherical models of collisionless but quasi-relaxed stellar systems have long been studied as a natural framework for the description of globular clusters. Here we consider the construction of self-consistent models under the same physical…

Astrophysics · Physics 2009-11-13 G. Bertin , A. L. Varri

We present two classes of inhomogeneous, spherically symmetric solutions of the Einstein-Maxwell-Perfect Fluid field equations with cosmological constant generalizing the Vaidya-Shah solution. Some special limits of our solution reduce to…

General Relativity and Quantum Cosmology · Physics 2019-10-09 Metin Gurses , Yaghoub Heydarzade

In this article we obtain a new anisotropic solution for Einstein's field equation of embedding class one metric. The solution is representing the realistic objects such as $Her~X-1$ and $RXJ~1856-37$. We perform detailed investigation of…

General Physics · Physics 2016-04-27 S. K. Maurya , Y. K. Gupta , Baiju Dayanandan , Saibal Ray