  We review recent developments on the role of neutrino mixing in the inverse
beta decay of accelerated protons. We show that calculations in the inertial
and comoving frames agree (thus preserving General Covariance) only when taking
neutrino asymptotic states to be flavor (rather than mass) eigenstates. Our
conclusions are valid in the approximation in which Pontecorvo states are
correctly representing neutrino flavor states. We speculate about the general
case involving exact flavor states and finally comment on other approaches
recently appeared in literature.
