Near-future discovery of point sources of ultra-high-energy neutrinos

Upcoming neutrino telescopes may discover ultra-high-energy (UHE) cosmic neutrinos, with energies beyond 100 PeV, in the next 10–20 years. Their sources are guaranteed interactions sites of UHE cosmic rays. We propose to identify sources via search of multiplets of UHE neutrinos from similar directions. We provide state-of-the-art forecasts of their detection in the radio array of IceCube-Gen2. We find that sources at declination of $−45^\circ$ to $0^\circ$ will be easiest to discover. Discovering even one steady-state source in 10 years would imply that the source has an UHE neutrino luminosity at least larger than about $10^{43}$ erg s$^{−1}$ (depending on the source redshift evolution). Discovering no transient source would disfavor transient sources brighter than $10^{53}$ erg as dominant.