2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42613With the recent experimental advance in our precise knowledge of the neutrino oscillation parameters, the correct form of the 3 X 3 neutrino mass matrix is now approximately known. I discuss how this may be obtained from symmetry principles, using as examples the finite groups A_4 and Z_4, predicting as a result three nearly degenerate Majorana neutrino masses in the 0.2 eV range.14 pages, talk at BEYOND 2003High Energy Physics - Phenomenologytext