The origin of cosmic rays and dark matter
The last three years have seen unprecedented developments in the field of the physics of cosmic rays, both from an observational and theoretical point of view. Observations made with the Cherenkov, MAGIC, VERITAS and HESS telescopes have led to the detection of high energy gamma-rays from supernova remnants, the most plausible sources of Galactic cosmic rays. From a theoretical point of view, recent years have seen the development of a non-linear theory for particle acceleration in supernova remnants, a crucial ingredient for the understanding of the origin of cosmic rays and to describe the multi-frequency observations of these sources.
Studies into the origin of cosmic rays have a long tradition in Italy and the Italian community continues to play an extremely important and active role today. This is illustrated not only by the number of scientists of various levels involved, for example, in the search for sources with the Fermi satellite or the operation of PAO, but also by the importance and resonance of the results achieved. INAF is also providing a key contribution to the hardware of the MAGIC-II telescope.
There have been two important developments in the last three years on the theoretical/phenomenological side: 1) the formalisation of a non-linear theory for particle acceleration in shock waves, 2) the development of the model of the dip for the transition of Galactic and extragalactic cosmic rays. Forthcoming years will be a golden period for the field of cosmic ray research given that the Fermi telescope and Cherenkov telescopes and ground-based detectors are already inundating the field with precious data. Italian groups have provided a fundamental contribution to this field, and will continue to investigate the many aspects that are still unclear, from the connection between supernova remnants and and cosmic rays observed from the Earth to the extension of studies of the interaction between cosmic rays and the region around the source. In this field, use is made of large structures such as KASCADE Grande, the Pierre Auger Observatory, MAGIC and Jem-EUSO.