On the mass neutrino phase along the geodesic line and the null line in curved and flat spacetime

On the mass neutrino phase calculations along both the particle geodesic line and the photon null line, there exists a double counting, a factor of 2, when comparing the geodesic phase with the null phase. Moreover, we compare the phase calculations with the same-energy description and the same-momentum description by means of the Minkowski diagram, and obtain the practical equivalence of these two descriptions. On the same-velocity description, although not corresponding any real physical process, we still indicate its phase calculation in the Minkowski diagram, which has the same result as those of same-energy and same-momentum cases. Furthermore, in the curved space-time, we also prove the existence of the double counting of the geodesic phase to the null phase. Our conclusions axe the same as others' results by the different methods.