We look for cosmic neutrinos originating in Gamma Ray bursts using public data from the IceCube collaboration. We allow for a time difference between a neutrino and GRB photon of up to 40 days to...Show moreWe look for cosmic neutrinos originating in Gamma Ray bursts using public data from the IceCube collaboration. We allow for a time difference between a neutrino and GRB photon of up to 40 days to probe possible Lorentz invariance violations. These violations might become visible if a neutrino has high enough energy and traveled a long enough distance before we observe it. We make use of pseudo experiments to simulate different possible neutrino realizations and see how well a signal can be discerned from background. We find slightly less neutrinos than expected from background in the IceCube data. A signal associated with more than 3% of the GRBs can be excluded at 98% confidence in the northern hemisphere, and at 70% confidence in the southern hemisphere. Under the assumption that the highest energy neutrinos that can be associated to a GRB are experiencing LIV induced time shifts we have derived an intrinsic time difference at emission between GRB neutrinos and photons of ∆tin = (4.49 ± 23.0) 10^4s, and a LIV scale of ELIV = (1.05 ± 0.85) 10^15GeV, while the probability of finding similar results from purely uncorrelated events is P = 54%.Show less
