Neutrinos in coincidence with GWs from LIGO/Virgo

Both low-energy (7-100MeV) and high-energy (0.1-105GeV) samples were analyzed in order to cover a very wide neutrino spectrum. Follow-ups of 36 (out of 39) gravitational waves reported in the GWTC-2 catalog were examined; no significant excess above the background was observed, with 10 (24) observed neutrinos compared with 4.8 (25.0) expected events in the high-energy (low- energy) samples.

A statistical approach was used to compute the significance of potential coincidences. For each observation, p-values were estimated using neutrino direction and LVC sky map; the most significant event (GW190602_175927) is associated with a post-trial p-value of 7.8% (1.4{sigma}). Additionally, flux limits were computed independently for each sample and by combining the samples.