  The photon-neutrino process gamma gamma -> nu bar nu and photon splitting are
considered in a strong magnetic field. The partial polarization amplitudes are
calculated within the standard model in the limit of a strong field. The
amplitudes do not depend on the field strength in this limit. Using the vector
parts of the amplitudes, the process of the photon splitting gamma -> gamma
gamma is investigated both below and above the pair creation threshold. The
splitting probabilities are calculated taking account of the photon dispersion
and large radiative corrections near the resonance.
