Light Sterile Neutrino and Dark Matter in Left-Right Symmetric Models
  Without Higgs Bidoublet
  We present a class of left-right symmetric models where Dirac as well as
Majorana mass terms of neutrinos can arise at one-loop level in a scotogenic
fashion: with dark matter particles going inside the loop. We show the
possibility of naturally light right handed neutrinos that can have interesting
implications at neutrinoless double beta decay experiments as well as
cosmology. Apart from a stable dark matter candidate stabilised by a remnant
$Z_2$ symmetry, one can also have a long lived keV sterile neutrino dark matter
in these models. This class of models can have very different collider
signatures compared to the conventional left-right models.
