Cold Dark Matter, Radiative Neutrino Mass, mu to e gamma, and   Neutrinoless Double Beta Decay
  Two of the most important and pressing questions in cosmology and particle physics are: (1) What is the nature of cold dark matter? and (2) Will near-future experiments on neutrinoless double beta decay be able to ascertain that the neutrino is a Majorana particle, i.e. its own antiparticle? We show that these two seemingly unrelated issues are intimately connected if neutrinos acquire mass only because of their interactions with dark matter. 
Jisuke Kubo, Ernest Ma, and Daijiro Suematsu