No-go for exactly degenerate neutrinos at high scale?
  We show in a model independent manner that, if the magnitudes of Majorana masses of neutrinos are exactly equal at some high scale, the radiative corrections cannot reproduce the observed masses and mixing spectrum at the low scale, irrespective of the Majorana phases or the mixing angles at the high scale. 
Amol S. Dighe, Anjan S. Joshipura