Neutrinoless double beta decay and neutrino physics
  The connection of neutrino physics with neutrinoless double beta decay is
reviewed. After presenting the current status of the PMNS matrix and the
theoretical background of neutrino mass and lepton mixing, we will summarize
the various implications of neutrino physics for double beta decay. The
influence of light sterile neutrinos and other exotic modifications of the
three neutrino picture is also discussed.
