T non-conservation in three-neutrino oscillations

The effects of a T violating vacuum mixing parameter in neutrino oscillations can be enhanced by the presence of matter. However, most astrophysical neutrino experiments observe only the electron neutrino transmission probability, P(νe; x → νe, y), which is completely independent of the T violating phase. There is only one direct measure of this phase for three favors and a symmetric medium such as the earth - for which we calculate some examples. (orig.)