IceCube Studies of the Three-Flavour Composition of Astrophysical Neutrinos

The IceCube Neutrino Observatory measures astrophysical and atmospheric neutrinos from the entire sky via the Cherenkov light emitted when these neutrinos interact in the ice and produce secondary particles like leptons or hadrons. The Medium Energy Starting Events (MESE) data sample selects events with vertices contained inside the detector volume and have energies from 1 TeV and above. This event selection includes neutrinos of all flavours from the entire sky. We use this data sample to constrain the astrophysical flavour ratio of neutrinos, and I will present these results in this talk.