Complementary Ansatz for the neutrino mass matrix
  We propose a simple Ansatz for the three generation neutrino mass matrix $M_\nu$ which is motivated from an SO(10) grand unified theory. The Ansatz can be combined with information from neutrino oscillation experiments and bounds on neutrinoless double beta decay to determine the neutrino masses themselves and to reconstruct, with some assumptions, the matrix $ M_\nu $ . 
D. Black, A. H. Fariborz, S. Nasri, J. Schechter