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Related papers: Gravitational collapse for a radiating anisotropic…

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The paper deals with collapse dynamics of a spherically symmetric massive star in the framework of non-equilibrium themodynamic prescription through particle creation mechanism. The matter content in the star is in the form of perfect uid…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Sudipto Bhattacharjee , Subhajit Saha , Subenoy Chakraborty

We describe the transition of a graviationally radiating, axially and reflection symmetric dissipative fluid, to a non--radiating state. It is shown that very shortly after the end of the radiating regime, at a time scale of the order the…

General Relativity and Quantum Cosmology · Physics 2018-10-17 L. Herrera , A. Di Prisco , J. Ospino

Within the metric formalism of $f(R)$ theories of gravity, where $R$ is the Ricci scalar, we study the hydrostatic equilibrium structure of compact stars with the inclusion of anisotropic pressure. In particular, we focus on the $f(R)=…

General Relativity and Quantum Cosmology · Physics 2022-07-11 Juan M. Z. Pretel , Sergio B. Duarte

We solve the dynamical GR equations for the spherically symmetric evolution of compact stars in the vicinity of the maximum mass, for which instability sets in according to linear perturbation theory. The calculations are done with the…

General Relativity and Quantum Cosmology · Physics 2015-08-06 Alessandro Brillante , Igor Mishustin

This article reports results from numerical simulations of the gravitational radiation emitted from nonrotating relativistic stars as a result of the axisymmetric accretion of layers of perfect fluid matter, shaped in the form of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alessandro Nagar , Guillermo Diaz

We investigate electromagnetic and gravitational radiation generated during the process of the tidal stripping of a white dwarf star circulating a black hole. We go beyond Chandrasekhar's ideas and not only consider a white dwarf itself as…

High Energy Astrophysical Phenomena · Physics 2025-03-10 Marek Nikołajuk , Tomasz Karpiuk , Lorenzo Ducci , Mirosław Brewczyk

Observational advances over the last decade reveal that star formation is associated with the simultaneous presence of gravitationally collapsing gas, bipolar outflow, and an accretion disk. Two theoretical views of star formation suppose…

Astrophysics · Physics 2007-05-23 R. E. Pudritz , D. E. McLaughlin , R. Ouyed

General Relativistic Entropic Acceleration (GREA) gives a general framework in which to study multiple out-of-equilibrium phenomena in the context of general relativity, like the late accelerated expansion of the universe or the formation…

General Relativity and Quantum Cosmology · Physics 2023-02-20 Juan Garcia-Bellido

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 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

The present work deals with dynamics of gravitational collapse with cylindrical symmetry as developed by Misner and Sharp. The interior collapsing anisotropic cylindrical perfect fluid is matched to an exterior vacuum cylindrically…

General Relativity and Quantum Cosmology · Physics 2016-03-08 Sanjukta Chakraborty , Subenoy Chakraborty

We present an analytic description of the spherically symmetric gravitational collapse of radiatively cooling gas clouds, which illustrates the mechanism by which radiative cooling induces gravitational instability at a characteristic mass…

Astrophysics of Galaxies · Physics 2025-01-03 James Gurian , Boyuan Liu , Donghui Jeong , Takashi Hosokawa , Shingo Hirano , Naoki Yoshida

We found equilibrium conditions for a self-gravitating toroidal vortex by taking into account thermal pressure. These conditions are shown to significantly differ from those for a disk and a sphere. The evolution of a thin vortex turns it…

Astrophysics · Physics 2009-11-10 K. Yu. Bliokh , V. M. Kontorovich

We study the gravitational collapse of a rotating cylindrical null shell with flat interior and the metric of a spinning cosmic string as the exterior. We see that there is a critical radius, where the energy density of the shell vanishes…

General Relativity and Quantum Cosmology · Physics 2015-05-30 S. Khakshournia

In this paper we investigate the gravothermal instability of spherical stellar systems endowed with a radially anisotropic velocity distribution. We focus our attention on the effects of anisotropy on the conditions for the onset of the…

Astrophysics · Physics 2009-10-30 M. Magliocchetti , G. Pucacco , E. Vesperini

A massive star undergoes a continual gravitational collapse when the pressures inside the collapsing star become insufficient to balance the pull of gravity. The Physics of gravitational collapse of stars is well studied. Using general…

General Relativity and Quantum Cosmology · Physics 2019-07-31 Dipanjan Dey , Pankaj S. Joshi

We study secular stability against a quasi-radial oscillation for rigidly rotating stars with soft equations of state in general relativity. The polytropic equations of state with polytropic index $n$ between 3 and 3.05 are adopted for…

Astrophysics · Physics 2009-11-10 Masaru Shibata

We present a study of shearfree gravitational collapse using cylindrically symmetric spacetimes whose interior is a non-rotating dissipative fluid bounded by a cylindrical hypersurface beyond which is an Einstein-Rosen vacuum exterior. We…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Marie-Noëlle Célérier , Nilton O. Santos

We compute the rates of capture of stars by supermassive black holes, using time-dependent Fokker--Planck equation with initial conditions that have a deficit of stars on low-angular-momentum orbits. One class of initial conditions has a…

Astrophysics of Galaxies · Physics 2015-08-06 Kirill Lezhnin , Eugene Vasiliev

Long Gamma Ray Bursts (GRBs) originate from the collapse of massive, rotating stars. We aim to model the process of stellar collapse in the scenario of a self-gravitating collapsing star. We account for the changes in Kerr metric induced by…

High Energy Astrophysical Phenomena · Physics 2023-08-30 Agnieszka Janiuk , Narjes Shahamat Dehsorkh , Dominika Krol