Neutrino Mass and Mixing in Astrophysics and Cosmology

Astrophysical considerations may provide a probe of the properties of the mysterious neutrinos. I discuss how neutrino mass and flavor oscillations can be important in astrophysical environments like the early universe, cosmology, and core collapse supernovae. For example, supercomputer supernova simulations reveal that neutrino flavor transformation and, consequently, the expected supernova neutrino signal, can depend sensitively on the as yet unmeasured neutrino mass hierarchy and the mixing angle $\theta_{1 3}$, both targets of on-going experimental efforts. Likewise, I will argue that other aspects of neutrino physics, untestable in the laboratory, nevertheless have consequences for the physics of stellar collapse, nucleosynthesis, the early universe, and cosmology.