Neutrino spin-flip effects in active galactic nuclei

We study the effects of neutrino spin-flip in the magnetic field, B_{AGN}, of active galactic nuclei (AGN) for high-energy neutrinos (E > 10^{6} GeV) originating from AGN induced by an interplay of the violation of equivalence principle parameterized by $\Delta f$ and the twist in B_{AGN}. We point out that a conversion effect may exist for $\Delta f \sim 10^{-34} (\delta m^{2}/10^{-5} eV^{2})$ independent of gravity mixing angle. Observational consequences for this conversion effect are discussed.