Numerical simulations of GRB engines

Gamma-ray burst central engines may be related with some of the most powerful astrophysical sources of gravitational radiation. Therefore, there are now several numerical models trying to elucidate both the details of the scenarios for the central engine and the information that gravitational waves could provide on the physical processes involved. The models are quite complex and they now consider full general-relativistic simulations, relativistic magneto-hydrodynamics and detailed microphysics for the description of very dense matter and neutrino interactions. This paper analyzes some of these numerical studies, trying to make a link with possible gravitational wave observations for both binary compact star mergers and massive star gravitational collapses.