Neutrino transport and the prompt mechanism for type II supernovae

Consideration is given to the possibility that a soft nuclear equation of state and general relativistic hydrodynamics can produce a shock with sufficient strength to propagate directly through a low-mass iron core during a stellar collapse. It is found that neutrino-electron scattering produces shock failure due to neutrino downscatter during collapse. Neutrino-electron scattering has little effect during shock propagation. It is shown that neutrino-matter energy exchange is important at densities below trapping density.