Neutrino physics - Theory

I discuss the new physics unveiled by neutrino oscillation experiments. It is fair to say that, while significant theoretical progress has been made, we are yet to construct a unique coherent picture that naturally explains non-zero, yet tiny, neutrino masses and the newly revealed pattern of lepton mixing. I discuss what the challenges are, and point to the fact that more experimental input is required. Finally, I draw attention to the fact that neutrinos may have only just begun to reshape fundamental physics, given the fact that we are still to explain the LSND anomaly and because the neutrino oscillation phenomenon is ultimately sensitive to very small new-physics effects.