Constraints on neutrino mass ordering and degeneracy from Planck and
  neutrino-less double beta decay
  We investigate constraints on neutrino mass ordering and degeneracy by
considering the first cosmological result based on Planck measurements of the
cosmic microwave background. It is shown that the result at 95% CL rejects a
neutrino mass degeneracy larger than 85% (82.5%) for the normal (inverted)
hierarchical case. We can also find some regions where the neutrino mass
ordering will be able to be distinguished by combining a value of sum of the
neutrino masses with an effective neutrino mass determined by neutrino-less
double beta decay experiments.
