High-energy astrophysics has radically evolved over the last few years, with the advent of multi-messenger astronomy: violent cosmic phenomena have been observed in gravitational waves (GWs) and with electromagnetic (EM) counterparts, and associations have been reported between very high neutrinos energy (10^15 eV) and photons at different wavelengths. The next frontier of high-energy astrophysics is EeV (10^18 eV) or ultra-high energy (UHE) multi-messenger astronomy. The detection of EeV neutrinos in particular should solve the long-standing mystery of the origin of UHE cosmic rays and open a unique window to cast light on the workings of the most violent sources in the Universe. The Giant Radio Array for Neutrino Detection (GRAND) is one of the most promising project to achieve the detection of these highly-seeked particles in the next decade. GRAND is a proposal for an array of 200’000 radio antennas deployed over 200’000km² in various favorable locations around the world, detecting cosmic particles (neutrinos, but also gamma rays and cosmic rays) of ultra high energy through the electromagnetic transient pulses they induce in the atmosphere when they reach the Earth. On the road to achieve this very ambitious project, a 300-unit prototype is being deployed in a remote area of the Gobi desert in China, complemented by a 10-units mini-array on the site of the Pierre Auger Observatory, deployed earlier this year. In this presentation, we will detail the scientific motivation, detection principle and expected outcomes of the GRAND project and present the different phases of the GRAND project.
Daniel kerszberg