  We report on the stellar core collapse, bounce, and postbounce evolution of a
13 solar mass star in a self-consistent general relativistic spherically
symmetric simulation based on Boltzmann neutrino transport. We conclude that
approximations to exact neutrino transport and omission of general relativistic
effects were not alone responsible for the failure of numerous preceding
attempts to model supernova explosions in spherical symmetry. Compared to
simulations in Newtonian gravity, the general relativistic simulation results
in a smaller shock radius. We however argue that the higher neutrino
luminosities and rms energies in the general relativistic case could lead to a
larger supernova explosion energy.
