Dr. Felix Riehn (Lab. Inst. Fisica Experim. Particulas)
"Interactions of ultra-high energy cosmic rays"
Ultra-high energy cosmic rays are the most energetic particles observed in nature. As such they provide a unique view to the universe at its most extreme. In this presentation I will focus on the interactions of UHECR in the atmosphere. I will summarize the current observations and discuss what these observations imply about the nature of particle interactions at the highest energies and what may still be learned in the future.