Prof. Michael Kachelrieß (NTNU): Physics of High-Energy Cosmic Rays

The observation of cosmic rays with energies beyond 10^20 eV is one of the most intriguing puzzles in astroparticle physics. After a review of the current experimental data and efforts, I discuss the open theoretical questions in this field. Among these unresolved issues, I emphasize as key problem the question if "charged particle astronomy" is possible. Finally, if time permits, I discuss "multi-messenger" astronomy, i.e. the connection between cosmic ray, gamma-ray and neutrino observations.