Dynamical Neutrino Mass Matrix: Large (Small) Mixing Solution to Atmospheric (Solar) Neutrino Oscillations

In the wake of the SuperKamiokande announcement of atmospheric neutrino oscillations which favor the large mixing of $\nu_\mu$ with $\nu_\tau$, there is considerable theoretical activity towards a possible understanding of the solar neutrino deficit also in terms of the mixing of $\nu_e$ with the other two neutrinos. A specific dynamical model is presented here for the first time which naturally chooses the large (small) mixing solution to atmospheric (solar) neutrino oscillations.