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Related papers: Complexity factors for axially symmetric static so…

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By applying a recent method --based on a tetrad formalism in General Relativity and the orthogonal splitting of the Riemann tensor-- to the simple spherical static case, we found that the only static solution with homogeneous energy density…

General Relativity and Quantum Cosmology · Physics 2018-10-24 J. Ospino , J. L. Hernández-Pastora , H. Hernández , L. A. Núñez

This paper uses the definition of complexity for a static spherically symmetric spacetime and extends it to the case of charged distribution. We formulate the Einstein-Maxwell field equations corresponding to the anisotropic interior and…

General Relativity and Quantum Cosmology · Physics 2023-06-02 M. Sharif , Tayyab Naseer

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

We review a recently proposed definition of complexity of the structure of self--gravitating fluids \cite{ch1}, and the criterium to define the simplest mode of their evolution. We analyze the origin of these concepts and their possible…

General Relativity and Quantum Cosmology · Physics 2023-04-13 L. Herrera

By a choice of new variables the pressure isotropy condition for spherically symmetric static perfect fluid spacetimes can be made a quadratic algebraic equation in one of the two functions appearing in it. Using the other variable as a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gyula Fodor

This paper aims to formulate certain scalar factors associated with matter variables for self-gravitating non-static cylindrical geometry by considering a standard model $\mathcal{R}+\zeta\mathcal{Q}$ of…

General Relativity and Quantum Cosmology · Physics 2023-11-02 M. Sharif , T. Naseer

An algorithm recently presented by Lake to obtain all static spherically symmetric perfect fluid solutions, is extended to the case of locally anisotropic fluids (principal stresses unequal). As expected, the new formalism requires the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. Herrera , J. Ospino , A. Di Prisco

All axisymmetric self-similar equilibria of self-gravitating, rotating, isothermal systems are identified by solving the nonlinear Poisson equation analytically. There are two families of equilibria: (1) Cylindrically symmetric solutions in…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev , Ramesh Narayan

The article is devoted to cosmology. It deals with homogeneous anisotropic cosmological models. Scale factors have been evaluated for the multicomponent models with perfect fluid, taking account of its expansion, rotation and shear. The…

General Relativity and Quantum Cosmology · Physics 2019-06-10 K. K. Ernazarov

A general procedure to find static and axially symmetric, interior solutions to the Einstein equations is presented. All the so obtained solutions, verify the energy conditions for a wide range of values of the parameters, and match…

General Relativity and Quantum Cosmology · Physics 2016-11-07 J. L. Hernandez-Pastora , L. Herrera , J. Martin

When solving the equations of General Relativity in a symmetric sector, it is natural to consider the same symmetry for the geometry and stress-energy. This implies that for static and isotropic spacetimes, the most general natural…

General Relativity and Quantum Cosmology · Physics 2015-05-14 Tomasz Konopka

In this paper, we investigate complexity of anisotropic cylindrical object under the influence of electromagnetic field in $f(G,T)$ theory, where $G$ and $T$ indicate the Gauss-Bonnet term and trace of the stress-energy tensor,…

General Relativity and Quantum Cosmology · Physics 2023-01-12 M. Sharif , Komal Hassan

Recent studies have shown the fluid of hard right triangles to possess fourfold and quasi-eightfold (octatic) orientational symmetries. However, the standard density-functional theory for two-dimensional anisotropic fluids, based on…

Soft Condensed Matter · Physics 2022-03-18 Yuri Martinez-Raton , Enrique Velasco

In this article, a special static spherically symmetric perfect fluid solution of Einstein's equations is provided. Though pressure and density both diverge at the origin, their ratio remains constant. The solution presented here fails to…

General Physics · Physics 2009-09-29 F. Rahaman , M. Kalam , S. Chakraborty , K. Maity , B. Raychaudhuri

Spherically symmetric static fluid sources are endowed with rotation and embedded in Kerr empty space-time up to an including quadratic terms in an angular velocity parameter using Darmois junction conditions. Einstein's equation's for the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Ron Wiltshire

In this article we consider the inhomogeneous incompressible Euler equations describing two fluids with different constant densities under the influence of gravity as a differential inclusion. By considering the relaxation of the…

Analysis of PDEs · Mathematics 2021-06-15 Björn Gebhard , József J. Kolumbán , László Székelyhidi

We carry out a general study on the collapse of axially (and reflection) symmetric sources in the context of general relativity. All basic equations and concepts required to perform such a general study are deployed. These equations are…

General Relativity and Quantum Cosmology · Physics 2015-06-19 L. Herrera , A. Di Prisco , J. Ibañez , J. Ospino

We consider anisotropic fluids with directional pressures $p_i = w_i \rho$ ($\rho$ is the density, $w_i = $const, $i = 1,2,3$) as sources of gravity in stationary cylindrically symmetric space-times. We describe a general way of obtaining…

General Relativity and Quantum Cosmology · Physics 2019-06-19 S. V. Bolokhov , K. A. Bronnikov , M. V. Skvortsova

We study the general properties of dissipative fluid distributions endowed with hyperbolical symmetry. Their physical properties are analyzed in detail. It is shown that the energy density is necessarily negative and the fluid distribution…

General Relativity and Quantum Cosmology · Physics 2021-09-17 L. Herrera , A. Di Prisco , J. Ospino

The aim of this paper is to present the definition of complexity for static self-gravitating anisotropic matter proposed in $f(G,T)$ theory, where $G$ is the Gauss-Bonnet term and $T$ is the trace of energy momentum tensor. We evaluate…

General Physics · Physics 2021-08-30 Z. Yousaf , Kazuharu Bamba , M. Z. Bhatti , K. Hassan