A relation between θ13 and the leptonic Dirac CP phase in SO(10) lopsided models

It is shown that in SO(10) models where the large solar and atmospheric neutrino angles come from the charged-lepton mass matrix being “lopsided”, there is a characteristic relation between the 13 mixing angle of the neutrinos and the size of the Dirac CP-violating phase in the lepton sector. This is illustrated in a recently proposed realistic and predictive model.