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We discuss the physical features of two recent classes of analytical solutions of the Einstein equations sourced by an exotic perfect fluid with equation of state $ P=-\rho/5$. These geometries depend on up to four parameters and are static…

General Relativity and Quantum Cosmology · Physics 2022-05-11 Behnaz Fazlpour , Ali Banijamali , Valerio Faraoni

The general properties of a perfect relativistic fluid resulting from the quantum gravitational anomaly are investigated. It is found that, in the limit of a weak gravitational field, this fluid possesses a polytropic equation of state…

High Energy Physics - Theory · Physics 2015-02-09 P. O. Kazinski

Stochastic perturbations (radial) of a spherically symmetric relativistic star, modeled by a perfect fluid in comoving coordinates for the collapse scenario are worked out using the classical Einstein- Langevin equation, which has been…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Seema Satin

We develop here a new procedure within Einstein's theory of gravity to generate equilibrium configurations that result as the final state of gravitational collapse from regular initial conditions. As a simplification, we assume that the…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Pankaj S. Joshi , Daniele Malafarina , Ramesh Narayan

We present the results of numerical simulations of the spherically symmetric gravitational collapse of supermassive stars (SMS). The collapse is studied using a general relativistic hydrodynamics code. The coupled system of Einstein and…

Astrophysics · Physics 2009-11-06 Felix Linke , Jose A. Font , Hans-Thomas Janka , E. Mueller , Philippos Papadopoulos

In the spirit of the Newtonian theory, we characterize spherically symmetric empty space in general relativity in terms of energy density measured by a static observer and convergence density experienced by null and timelike congruences. It…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Naresh Dadhich

We study the collapse of spherical cold clouds beyond black hole formation to investigate the possibility of a bounce in the in-falling matter when a critical density or pressure is reached. As a first step, we analyse the pressureless…

General Relativity and Quantum Cosmology · Physics 2025-01-24 Swaraj Pradhan , Michael Gabler , Enrique Gaztañaga

We establish the formalism in the nonsymmetric gravitational theory (NGT) for stellar equilibrium and gravitational collapse. We study the collapse of a pressureless, spherically symmetric dust cloud. By assuming that the interior solution…

Astrophysics · Physics 2008-02-03 J. W. Moffat

A class of spherically symmetric spacetimes invariantly defined by a zero flux condition is examined first from a purely geometrical point of view and then physically by way of Einstein's equations for a general fluid decomposition of the…

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

We present a new class of solutions to Einstein equations for the spherical collapse of dustlike matter coupled with heat flux. In this family of solutions spacetime shear is necessarily non-zero. Also these solutions have an interesting…

General Relativity and Quantum Cosmology · Physics 2007-07-11 Rituparno Goswami

The aim of the present letter is to explain the `critical behaviour' observed in numerical studies of spherically symmetric gravitational collaps of a perfect fluid. A simple expression results for the critical index $\gamma$ of the black…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Dieter Maison

We study critical phenomena in the gravitational collapse of a radiation fluid. We perform numerical simulations in both spherical symmetry and axisymmetry, and observe critical scaling in both supercritical evolutions, which lead to the…

General Relativity and Quantum Cosmology · Physics 2016-01-08 Thomas W. Baumgarte , Pedro J. Montero

In this paper, we discuss the spherically symmetric gravitational collapse of matter fields in the de Sitter universe. The energy-momentum tensor of the matter field is assumed to admit a wide variety including dust, perfect fluids with…

General Relativity and Quantum Cosmology · Physics 2026-05-15 Akriti Garg , Ayan Chatterjee

Following our result that for the final state of continued spherical gravitational collapse, the gravitational mass of the fluid, $M_f\to 0$, we show that for a physical fluid the eventual value of $2GM_f/R_f\to 1$ rather than $2GM_f/R_f…

Astrophysics · Physics 2007-05-23 Abhas Mitra

Spherically symmetric static solutions of the Einstein equations with a positive cosmological constant for the energy-momentum tensor of a barotropic perfect fluid are governed by the Tolman-Oppenheimer-Volkoff-de Sitter equation. Existence…

Analysis of PDEs · Mathematics 2016-03-09 Tetu Makino

We study the static stellar equilibrium configurations ofuncharged and charged spheres composed by a relativistic polytropic fluid, and compare with those of spheres composed by a non-relativistic polytropic fluid, the later case already…

General Relativity and Quantum Cosmology · Physics 2018-05-30 José D. V. Arbañil , Vilson T. Zanchin

We consider the gravitational collapse of a spherically symmetric homogeneous matter distribution consisting of a Weyssenhoff fluid in the presence of a negative cosmological constant. Our aim is to investigate the effects of torsion and…

General Relativity and Quantum Cosmology · Physics 2017-04-19 Amir Hadi Ziaie , Paulo Vargas Moniz , Arash Ranjbar , Hamid Reza Sepangi

We construct an exact quantum gravitational state describing the collapse of an inhomogeneous spherical dust cloud using a lattice regularization of the Wheeler-DeWitt equation. In the semiclassical approximation around a black hole, this…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Cenalo Vaz , Louis Witten , T. P. Singh

We examine static perfect fluid spheres in the presence of a cosmological constant. New exact matter solutions are discussed which require the Nariai metric in the vacuum region. We generalize the Einstein static universe such that neither…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , Gyula Fodor

We model a compact radiant star that undergoes gravitational collapse from a certain initial static configuration until it becomes a black hole. The star consists of a fluid with anisotropy in pressures, bulk viscosity, in addition to the…

General Relativity and Quantum Cosmology · Physics 2023-04-26 A. C. Mesquita , M. F. A. da Silva