Constraining dynamical neutrino mass generation with cosmological data
  We study models in which neutrino masses are generated dynamically at
cosmologically late times. Our study is purely phenomenological and
parameterized in terms of three effective parameters characterizing the
redshift of mass generation, the width of the transition region, and the
present day neutrino mass. We also study the possibility that neutrinos become
strongly self-interacting at the time where the mass is generated. We find that
in a number of cases, models with large present day neutrino masses are allowed
by current CMB, BAO and supernova data. The increase in the allowed mass range
makes it possible that a non-zero neutrino mass could be measured in direct
detection experiments such as KATRIN. Intriguingly we also find that there are
allowed models in which neutrinos become strongly self-interacting around the
epoch of recombination.
