Common Origin of Active and Sterile Neutrino Masses with Dark Matter
  We propose an abelian extension of the Standard Model which can explain the
origin of eV scale masses and mixing for active and sterile neutrinos and at
the same time providing a natural cold dark matter candidate. One of the three
active neutrinos acquires mass at tree level through seesaw mechanism whereas
the other two active neutrinos and one sterile neutrino acquire eV scale masses
at one-loop level. The model also allows non-trivial mixing between active and
sterile neutrinos at one-loop level which could have interesting signatures at
neutrino experiments. After the abelian gauge symmetry gets spontaneously
broken down to a $Z_2$ symmetry, the lightest $Z_2$ odd particle can naturally
give rise to the cold dark matter of the Universe. The phenomenology of both
fermionic and scalar dark matter is briefly discussed by incorporating latest
experimental constraints.
