Neutrinos from Supernovae and Gamma Ray Bursts: Nucleosynthesis and Detection

We discuss the way in which neutrino oscillations, sterile neutrinos and ambient conditions impact the nucleosynthesis in extreme astrophysical environments such as supernovae and gamma ray bursts. We focus first on r-process nucleosynthesis and supernovae and the role of neutrinos. Secondly, we discuss active sterile neutrino oscillations in this environment. We then turn to gamma ray bursts and examine the nucleosynthesis that can be produced by accretion disk winds, and the impact of the neutrinos. Finally we comment on the prospects for detecting such an accretion disk if it were to occur in the Galaxy with existing neutrino detectors.