COMS

Observations of high Energy gamma rays are performed: from space, by the Large Area Telescope onboard the Fermi satellite and by the AGILE satellite, and from Earth, by the Imaging Air Cherenkov Telescopes H.E.S.S., MAGIC and VERITAS, and by the Extensive Air Shower detector HAWC (under completion). These instruments have discovered different populations of gamma-ray emitters and studied in detail the non-thermal processes producing this high-energy radiation. Their scientific objectives include also questions related to fundamental physics. With gamma-ray instruments we study the origin of cosmic rays, and the cosmic electron-positron spectrum at high energies; moreover, we can search for signatures of dark matter. By observing the gamma-ray emission from sources at cosmological distances, we measure the intensity and evolution of the extragalactic background radiation, measure the energy of the cosmic vacuum searching for axion-like particles in a domain complementary to laboratory experiments, and perform tests of Lorentz Invariance. This is why the field is in rapid development, and many new experiments involving experimental particle physicists are in construction and in project.

All these questions can be tackled with the use of upcoming neutrino and gravitational waves facilities, the so-called new-messengers. First neutrino candidates from a cosmic source have been recently detected by IceCube but they could not be correlated with any precise astrophysical source. While no direct observation of gravitational waves has yet been claimed, it is widely believed that a first detection could plausibly occur in the near future. GRBs are among electromagnetic counterpart candidates, and a simultaneous detection would represent a major milestones bridging neutrino and gravitational wave observations with conventional astronomy.

Within this context, the theme of this conference is to evaluate the scientific merit of different options for a world-wide experimental neutrino program in the near future.