Search for low-energy Borexino's signals correlated with gamma-ray bursts, solar flares and gravitational wave events.

A.V. Derbin for the Borexino collaboration The results of a low-energy neutrino search using the Borexino detector in coincidence with gamma-ray bursts (GRB), solar flares (SF) and gravitational wave (GW) events are presented. The correlated events with energies greater than 0.25 (1.0) MeV were looked for within a various time windows centered around the GRB, SF or GW detection time. As a result, we have obtained the best current upper limits on all flavor neutrino fluences associated with these astrophysical sources for neutrino energy below 5-7 MeV.