The Universe is filled with an unimaginably rich diversity of phenomena and processes. Thanks to the rapid developments in observational astrophysics we have now an extensive electromagnetic observing window spanning from the radio waveband to the high energy gamma rays. Besides photons, however, there are also other carriers of information. Many of them, e.g. accelerated particles (cosmic rays), neutrinos, and gravitational waves, are thought to be created in the fireballs resulting from the most violent and energetic events, such as merging or exploding stars and ultra relativistic jets. The goal of this MIAPP programme is to identify the efforts required to bring us closer to the discovery of the most energetic accelerators in the Universe. 

We will confront questions such as: What are the sources making up the cosmic neutrinos detected by IceCube? Are these connected to the long standing mystery of the ultra high energy cosmic rays? How are cosmic rays accelerated and how do they lose energy during their propagation? Important clues hide in the details of the astrophysical scenarios, in the theoretical modelling, in the observational power of gamma-ray telescopes like Fermi, Magic, H.E.S.S, Veritas, HAWC, and CTA, and in the data collected by on-going experiments like IceCube, the Pierre Auger Observatory and Telescope Array.