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Related papers: Magnetized Tolman-Bondi Collapse

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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 study here the evolution of a massless scalar field in a spacetime, developing from a regular initial spacelike surface. The Einstein equations and regularity and boundary conditions governing the same are specified. Both homogeneous and…

General Relativity and Quantum Cosmology · Physics 2009-12-13 Swastik Bhattacharya , Rituparno Goswami , Pankaj S. Joshi

In this paper, we treat 4-dimensional Einstein-Gauss-Bonnet gravity as general relativity with an effective stress-energy tensor. We will study the modified Oppenheimer-Snyder-Datt model of the gravitational collapse of a star in a…

General Relativity and Quantum Cosmology · Physics 2023-02-22 R. Hassannejad , A. Sadeghi , F. Shojai

The potential importance of magnetic fields during structure formation and gravitational collapse in the early Universe has been shown in several studies. In particular, magnetic field amplification by the small-scale dynamo plays an…

Astrophysics of Galaxies · Physics 2024-01-09 V. B. Díaz , D. R. G. Schleicher , M. A. Latif , P. Grete , R. Banerjee

In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tanwi Bandyopadhyay , Subenoy Chakraborty

A study is undertaken of the gravitational collapse of spherically symmetric thick shells admitting a homothetic Killing vector field under the assumption that the energy momentum tensor corresponds to the absence of a pure outgoing…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Brien C. Nolan

Stars form by the gravitational collapse of interstellar gas. The thermodynamic response of the gas can be characterized by an effective equation of state. It determines how gas heats up or cools as it gets compressed, and hence plays a key…

Motivated by recent work on the structure of the singularity in inhomogeneous Tolman-Bondi collapse models, we investigate the behaviour of null geodesics in the particular case where the collapse is self-similar. The presence of the…

General Relativity and Quantum Cosmology · Physics 2025-02-13 Néstor Ortiz , Olivier Sarbach , Thomas Zannias

We will describe here the structure of singularity forming in gravitational collapse of spherically symmetric inhomogeneous dust. Such a collapse is described by the Tolman-Bondi-Lema{\^i}tre metric. The main new result here relates, in a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Jhingan

We have performed 2.5-dimensional general relativistic magnetohydrodynamic (MHD) simulations of the gravitational collapse of a magnetized rotating massive star as a model of gamma ray bursts (GRBs). This simulation showed the formation of…

Astrophysics · Physics 2009-11-10 Yosuke Mizuno , Shoichi Yamada , Shinji Koide , Kazunari Shibata

We investigate the dynamics of the ground state entanglement entropy for a discretized scalar field propagating within the Oppenheimer-Snyder collapse metric. Starting from a well-controlled initial configuration, we follow the system as it…

General Relativity and Quantum Cosmology · Physics 2025-11-12 Alessio Belfiglio , Orlando Luongo , Stefano Mancini , Sebastiano Tomasi

The dynamics of collapsing and expanding cylindrically symmetric gravitational and matter fields with lightlike wave-fronts is studied in General Relativity, using the Barrabes-Israel method. As an application of the general formulae…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Paulo R. C. T. Pereira , A. Z. Wang

The Raychaudhuri equations for the expansion, shear and vorticity are generalized in a spacetime with torsion for timelike as well as null congruences. These equations are purely geometrical like the original Raychaudhuri equations and…

General Relativity and Quantum Cosmology · Physics 2021-10-27 Sudipta Hensh , Stefano Liberati

We examine the role of the initial density and velocity distribution in the gravitational collapse of a spherical inhomogeneous dust cloud. Such a collapse is described by the Tolman-Bondi metric which has two free functions: the…

General Relativity and Quantum Cosmology · Physics 2009-10-22 T. P. Singh , P. S. Joshi

The acceleration parameter defined through the local volume expansion is negative for a pressureless, irrotational fluid with positive energy density. In the presence of inhomogeneities or anisotropies the volume expansion rate results from…

In the quantum Hall regime, the longitudinal resistivity $\rho_{xx}$ plotted as a density--magnetic-field ($n_{2D}-B$) diagram displays ringlike structures due to the crossings of two sets of spin split Landau levels from different subbands…

Mesoscale and Nanoscale Physics · Physics 2010-03-10 Gerson J. Ferreira , J. Carlos Egues

The magnetic fields affect collapse of molecular cloud cores. Here, we consider a collapsing core with an axial magnetic field and investigate its effect on infall of matter and formation of accretion disk. For this purpose, the equations…

Astrophysics of Galaxies · Physics 2015-05-27 Mohsen Nejad-Asghar

We studied the collapse of rotating molecular cloud cores with inclined magnetic fields, based on three-dimensional numerical simulations.The numerical simulations start from a rotating Bonnor-Ebert isothermal cloud in a uniform magnetic…

Astrophysics · Physics 2009-11-11 Masahiro N. Machida , Tomoaki Matsumoto , Tomoyuki Hanawa , Kohji Tomisaka

We examine the near collapse dynamics of a self-gravitating magnetized electron gas at finite temperature, taken as the source of a Bianchi-I spacetime described by the Kasner metric. The set of Einstein-Maxwell field equations reduces to a…

High Energy Physics - Theory · Physics 2012-11-27 I. Delgado Gaspar , A. Perez Martinez , Roberto A. Sussman , A. Ulacia Rey

We use both numerical and analytical approaches to study the dynamics of the gravitational collapse in the framework of the relativistic theory of gravitation (RTG). We use various equations of state for the collapsing matter and relatively…

General Relativity and Quantum Cosmology · Physics 2016-09-15 K. V. Antipin , A. I. Dubikovsky , P. K. Silaev
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