Title: High-energy Cosmic Rays: Puzzles, Models and Giga-ton Neutrino Telescopes


The existence of cosmic rays of energies exceeding 10^{20} eV is one of the great mysteries of high-energy astrophysics. The spectrum and the high energy to which it extends rule out almost all suggested source models. I will review the recent new experimental results, and their implications for theoretical models. I will show that model predictions may be tested with giga-ton neutrino detectors under construction, which may resolve the high-energy cosmic-ray puzzle and will shed light on the nature and physics of the most powerful accelerators in the universe.