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In this paper, we present an exact model of a spherically symmetric star undergoing dissipative collapse in the form of a radial heat flux. The interior of the star is matched smoothly to the generalized Vaidya line element representing a two-fluid atmosphere comprising null radiation and a string fluid. The influence of the string density on the thermal behavior of the model is investigated by employing a causal heat transport equation of Maxwell-Cattaneo form. [ABSTRACT FROM AUTHOR]

In this paper we revisit the problem of modeling radiating stars in which the areal radius is equal to the proper radius throughout the stellar evolution. We provide a new family of solutions that completely describes the dynamical behaviour of these so-called Euclidean stars. The solution satisfies all the energy conditions, and importantly, admits a barotropic equation of state. [ABSTRACT FROM AUTHOR]

We investigate the gravitational collapse of a radiating sphere evolving into a final static configuration described by the interior Schwarzschild solution. The temperature profiles of this particular model are obtained within the framework of causal thermodynamics. The overall temperature evolution is enhanced by contributions from the temperature gradient induced by perturbations as well as relaxational effects within the stellar core. [ABSTRACT FROM AUTHOR]

We investigate the causal temperature profiles in a recent model of a radiating star undergoing dissipative gravitational collapse without the formation of a horizon. It is shown that this simple exact model provides physically reasonable behaviour for the temperature profile within the framework of extended irreversible thermodynamics. [ABSTRACT FROM AUTHOR]

We study the effects of pressure anisotropy and heat dissipation in a spherically symmetric radiating star undergoing gravitational collapse. An exact solution of the Einstein field equations is presented in which the model has a Friedmann-like limit when the heat flux vanishes. The behavior of the temperature profile of the evolving star is investigated within the framework of causal thermodynamics. In particular, we show that there are significant differences between the relaxation time for the heat flux and the relaxation time for the shear stress. [ABSTRACT FROM AUTHOR]

In a recent paper [J. Math. Phys. 43, 4904 (2002)] Liu and Zhang present a time-dependent solution for a star which is immersed in a background radiation. This solution was obtained by analyzing equations arising from the analysis of a five-dimensional solution that contained their solution. We show that, while their analysis and conclusions are valid, their equations are unnecessarily restrictive when applied to the four-dimensional case. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]