Some Remarks on the Neutrino Oscillation Phase in a Gravitational Field
  The weak gravitational field expansion method to account for the gravitationally induced neutrino oscillation effect is critically examined. It is shown that the splitting of the neutrino phase into a ``kinematic'' and a ``gravitational'' phase is not always possible because the relativistic factor modifies the particle interference phase splitting condition in a gravitational field. 
J.G. Pereira, C. M. Zhang