The endgame of massive star evolution is the gravitational-induced collapse of the central inert iron core. The collapse of the core continues until the matter reaches nuclear densities where the strong force between nucleons becomes dominant and provides sufficient pressure to stabilize the newly formed protoneutron star. What ensues is a complex multi-physics problem involving strong gravity, multidimensional hydrodynamic instabilities, magnetic fields, multispecies neutrino radiation, and supranuclear density physics to name a few.
We expect that most massive stars end this final stage of stellar evolution with a successful core-collapse supernova explosion. However, we also know that some of these core collapse events must fail and form stellar mass black holes.In his talk I will touch on two of the most important questions in core-collapse supernovae theory. I will briefly talk about what conditions are favourable for failed core-collapse supernovae (i.e. black hole formation). Conversely, I will discuss recent results from full three-dimensional, general-relativistic simulations of core-collapse and the implications for our understanding of the core-collapse supernova mechanism. If time permits, I'll discuss how neutrinos from the next galactic core-collapse supernova can help constrain properties of massive stars.