Radiating spheres in general relativity with a mixed transport energy flow

Abstract

A semi-numerical method by Herreraet al. (1980) is extended to handle the evolution of general relativistic spheres where diffusion and free streaming radiation processes coexist. It is shown when mixed-mode radiation is present a very different hydrodynamic picture emerges from the models previously considered in both radiation limit. Characteristic times for free streaming, hydrodynamics, and diffusion processes are considered comparable. Hydrodynamics and radiation are strongly coupled and the particular equation of state of the model emerges as a very important element in the dynamic of the matter distribution.