The observation of neutrinos from cosmic accelerators will be revolutionary.
High energy neutrinos are closely connected to ultrahigh energy cosmic rays and
their sources. Cosmic ray sources are likely to produce neutrinos and the
propagation of ultrahigh cosmic rays from distant sources can generate PeV to
ZeV neutrinos. We briefly review recent progress on the observations of
ultrahigh energy cosmic rays and their implications for the future detections
of high energy neutrinos.Comment: 6 pages, 2 figures, Proceedings of NOW (Neutrino Oscillation
Workshop) 2010, to appear in Nucl. Phys. B (Proc. Suppl.