ALMOST DEGENERATE NEUTRINOS

The three experimental findings namely, deficits in the solar and atmo spheric neutrino fluxes and the need for a significant hot component i n the dark matter can be simultaneously reconciled with three light ne utrinos only if they are almost degenerate. A scenario proposed to und erstand this degeneracy and small departures from it is discussed. Sma ll differences in the neutrino masses arise in this scenario due to no n-zero up-quark or charged lepton masses. These are such that the hier archy \DELTA32\ >> \DELTA21\ (DELTA(ij) = m(vi)2 - m(vj)2) required fo r the simultaneous solution of the solar and atmospheric neutrino prob lem is correctly reproduced. Moreover, the common mass scale for the n eutrino is fixed to be in the eV range as required for the solution to the dark matter problem if one identifies the majorana masses of the right handed neutrinos with the grand unification scale. Possible mode ls leading to a realization of this scenario are discussed.