Relativistic, Spherically Symmetric Star Clusters.IV. a Sufficient Condition for Instability of Isotropic Clusters against Radial Perturbations

1970 ◽  
Vol 160 ◽  
pp. 859 ◽  
Author(s):  
Edward D. Fackerell





2011 ◽  
Vol 20 (11) ◽  
pp. 2239-2252 ◽  
Author(s):  
M. SHARIF ◽  
H. RIZWANA KAUSAR

We consider the modified f(R) theory of gravity whose higher-order curvature terms are interpreted as a gravitational fluid or dark source. The gravitational collapse of a spherically symmetric star, made up of locally anisotropic viscous fluid, is studied under the general influence of the curvature fluid. Dynamical equations and junction conditions are modified in the context of f(R) dark energy and by taking into account the expansionfree evolution of the self-gravitating fluid. As a particular example, the Skripkin model is investigated which corresponds to isotropic pressure with constant energy density. The results are compared with corresponding results in General Relativity.



2017 ◽  
Vol 26 (13) ◽  
pp. 1750142 ◽  
Author(s):  
Hasrat Hussain Shah ◽  
Quaid Iqbal

In this work, we study the gravitational collapsing process of a spherically symmetric star constitute of Dark Matter (DM), [Formula: see text], and Dark Energy (DE) [Formula: see text]. In this model, we use anisotropic pressure with Equation of State (EoS) [Formula: see text] and [Formula: see text], [Formula: see text]. It reveals that gravitational collapse of DM and DE with interaction leads to the formation of the black hole. When [Formula: see text] (phantoms), dust and phantoms could be ejected from the death of white hole. This emitted matter again undergoes to collapsing process and becomes the black hole. This study gives the generalization for isotropy of pressure in the fluid to anisotropy when there will be interaction between DM and DE.



2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Chris Sherlock ◽  
Daniel Elton

We present a class of spherically symmetric random variables defined by the property that as dimension increases to infinity the mass becomes concentrated in a hyperspherical shell, the width of which is negligible compared to its radius. We provide a sufficient condition for this property in terms of the functional form of the density and then show that the property carries through to equivalent elliptically symmetric distributions, provided that the contours are not too eccentric, in a sense which we make precise. Individual components of such distributions possess a number of appealing Gaussian-like limit properties, in particular that the limiting one-dimensional marginal distribution along any component is Gaussian.



1995 ◽  
Vol 36 (7) ◽  
pp. 3676-3693 ◽  
Author(s):  
Marcus Kriele


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