  We review the prospects for probing new physics with neutrino astrophysics.
High energy neutrinos provide an important means of accessing physics beyond
the electroweak scale. Neutrinos have a number of advantages over conventional
astronomy and, in particular, carry information encoded in their flavor degree
of freedom which could reveal a variety of exotic neutrino properties. We also
outline ways in which neutrino astrophysics can be used to constrain dark
matter properties, and explain how neutrino-based limits lead to a strong
general bound on the dark matter total annihilation cross-section.
