High energy phenomena in clusters of galaxies

Several phenomena in high energy astrophysics have been recently related to clusters of galaxies and to cosmic ray interactions occurring inside these structures. In many of these phenomena the observable effects depend on the energy density of cosmic rays confined in the Intra Cluster (IC) medium, which is a poorly known quantity. We propose here that useful indications about this quantity can be obtained from present and future observations in the radio and hard X-ray frequency ranges.