  Gamma-ray bursts (GRBs) are among the most powerful events observed in our
universe and have long been considered as possible sources of ultra-high-energy
cosmic rays, which makes them promising neutrino source candidates. Previous
IceCube searches for neutrino correlations with GRBs focused on the prompt
(main emission) phase of the GRB and found no significant correlation between
neutrino events and the observed GRBs. This motivates us to extend our search
beyond the prompt phase. We perform analyses looking for evidence of neutrino
emission up to 14 days before and after the prompt phase of GRBs. These
analyses rely on a sample of candidate muon-neutrino events observed by IceCube
from May 2011 to October 2018. The analyses are model-independent. Two of them
scan different time-windows for possible neutrino emission, while a third
analysis targets precursor emission based on GRB precursor observations by
Fermi-GBM. We discuss the results and implications of these searches including
limits on the contribution of GRBs to the diffuse neutrino flux.
