The roles of nuclear physics during stellar core collapse

Nuclear physics plays an important role during the collapse of a massive star and the subsequent Type II or Ib/c supernova. Of particular importance during core collapse and the initial evolution of the supernova shock are nuclear electron capture and the nuclear equation of state. The nuclear equation of state (EoS) controls the nature of the bounce which initially forms the supernova shock while electron capture alters the nuclear and leptonic composition, determining the location where the shock forms. There is a strong interplay between nuclear electron capture and the nuclear equation of state, as the rate of electron capture depends on the nuclear composition determined by the EoS, while the EoS is sensitive to the neutronization set by the weak interactions. We summarize recent progress in three investigations into the role of Nuclear Physics during core collapse. We explore the impact weak interactions with heavy nuclei have in supernovae across the range of supernova progenitors. We demonstrate that these effects are sensitive to variations in the electron capture rates at the level of their current uncertainty. Finally, we present simulations showing the impact of changes in the nuclear equation of state on supernova shock formation and propagation.