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In this paper, we consider the spherically symmetric gravitational collapse of isotropic matter undergoing dissipation in the form of heat flux, with a generalized Vaidya exterior, in the context of $f(R, T)$ gravity. Choosing $f(R,…

General Relativity and Quantum Cosmology · Physics 2025-08-11 Uttaran Ghosh , Sarbari Guha

We study the spherical collapse of non-top-hat matter fluctuations in the presence of dark energy with arbitrary sound speed. The model is described by a system of partial differential equations solved using a pseudo-spectral method with…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-22 R. C. Batista , H. P. de Oliveira , L. R. W. Abramo

We describe the quasi-static collapse of a radiating, spherical shell of matter in de Sitter space-time using a thermodynamical formalism. It is found that the specific heat at constant area and other thermodynamical quantities exhibit…

General Relativity and Quantum Cosmology · Physics 2008-11-26 G. L. Alberghi , R. Casadio , G. Venturi

We develop a general formalism to treat, in general relativity, the linear oscillations of a two-fluid star about static (non-rotating) configurations. Such a formalism is intended for neutron stars, whose matter content can be described,…

General Relativity and Quantum Cosmology · Physics 2009-10-31 G. L. Comer , David Langlois , Lap Ming Lin

This paper deals with the study of collapsing plane symmetric source in the presence of heat flux. For this purpose, we have calculated the Einstein field equations as well as Weyl tensor components. The conditions for the conformal…

General Physics · Physics 2015-08-24 G. Abbas , Zahid Ahmad , Hassan Shah

Spherical models of collisionless but quasi-relaxed stellar systems have long been studied as a natural framework for the description of globular clusters. Here we consider the construction of self-consistent models under the same physical…

Astrophysics · Physics 2009-11-13 G. Bertin , A. L. Varri

The present work deals with the dynamics of radiating star which is considered to be expansion free cylindrical symmetric dust dissipative fluids. Several treatments are adopted for the description of geometrical and physical features of…

General Relativity and Quantum Cosmology · Physics 2020-05-13 Rajesh Kumar , Sudhir Kumar Srivastava

Similarity solutions are found for the adiabatic collapse of density perturbations $\delta M/M \propto r^{-s}$ $(s>0)$ in a flat universe containing collisional gas only. The solutions are obtained for planar, cylindrical, and spherical…

Astrophysics · Physics 2008-11-26 Leonid Chuzhoy , Adi Nusser

In this work, we study the collapse dynamics of an inhomogeneous spherically symmetric star made of dark matter (DM) and dark energy (DE). The dark matter is taken in the form of a dust cloud while anisotropic fluid is chosen as the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Subenoy Chakraborty , Tanwi Bandyopadhyay

For the first time nonradial oscillations of superfluid nonrotating stars are self-consistently studied at finite stellar temperatures. We apply a realistic equation of state and realistic density dependent model of critical temperature of…

Solar and Stellar Astrophysics · Physics 2015-05-28 A. I. Chugunov , M. E. Gusakov

In a recent paper, one of us studied spherically symmetric, asymptotically flat solutions of Shape Dynamics, finding that the spatial metric has characteristics of a wormhole - two asymptotically flat ends and a minimal-area sphere, or…

General Relativity and Quantum Cosmology · Physics 2017-02-22 Flavio Mercati , Henrique Gomes , Tim Koslowski , Andrea Napoletano

In this paper, we test the spherical collapse of a unified dark fluid (UDF) which has constant adiabatic sound speed. By choosing the different values of model parameters $B_s$ and $\alpha$, we show the nonlinear collapse for UDF and…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-24 Lixin Xu

We consider a gravitating spherically symmetric nonrelativistic configuration consisting of a massless chameleon scalar field nonminimally coupled to a perfect isothermal fluid. The object of this paper is to show the influence of the…

Solar and Stellar Astrophysics · Physics 2012-01-11 Vladimir Folomeev

Starting off with two distinct initially static stellar cores (i) Florides interior (constant density, vanishing radial pressure) and (ii) Wyman interior (constant density, nonvanishing radial pressure), we explore the dynamics of these two…

General Relativity and Quantum Cosmology · Physics 2016-02-10 Nolene Ferrari Naidu , Megan Govender

Within the mirror dark matter model and dissipative dark matter models in general, halos around galaxies with active star formation (including spirals and gas rich dwarfs) are dynamical: they expand and contract in response to heating and…

Astrophysics of Galaxies · Physics 2018-05-23 R. Foot

We investigate the causal temperature profiles in a recent model of a radiating star undergoing dissipative gravitational collapse without the formation of an horizon. It is shown that this simple exact model provides a physically…

General Relativity and Quantum Cosmology · Physics 2007-05-23 N F Naidu , M Govender

A new model is proposed to a collapsing star consisting of an anisotropic fluid with bulk viscosity, radial heat flow and outgoing radiation. In a previous paper one of us has introduced a function time dependent into the $g_{rr}$, besides…

General Relativity and Quantum Cosmology · Physics 2013-01-14 G. Pinheiro , R. Chan

Gravitational collapse of a class of spherically symmetric stars are investigated. We quantise the geometries describing the gravitational collapse by a deformation quantisation procedure. This gives rise to noncommutative spacetimes with…

High Energy Physics - Theory · Physics 2011-02-09 Wen Sun , Ding Wang , Naqing Xie , R. B. Zhang , Xiao Zhang

We study the spherical collapse model for several dark energy scenarios using the fully nonlinear differential equation for the evolution of the density contrast within homogeneous spherical overdensities derived from Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Pace , J. -C. Waizmann , M. Bartelmann

Recent results from interferometry and asteroseismology require models of rapidly rotating stars that are more and more precise. We describe the basic structure and the hydrodynamics of a fully radiative star as a preliminary step towards…

Astrophysics · Physics 2007-06-13 F. Espinosa Lara , M. Rieutord
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