On a radiating fluid in a general relativistic context

A model for the radiation hydrodynamics in general relativity is analyzed,describing the gravitational collapse and supernovae explosion. As these physicalphenomena can be assumed spherically symmetric, the equations of motionfor a unique fluid, representing the interaction between matter and radiation,are written in a spherical symmetric space-time with respect to a comovingframe. The system is completed by using the Eddington closure, assuming alocal thermodynamical equilibrium for the radiation field. The resulting systemis analyzed by the Lie symmetry approach and a reduction to an ODEs systemis obtained. Numerical simulations of the solutions are performed, showing arealistic enough description of the physical phenomena.