Unified Origin of Dark Matter Self-Interactions and Low Scale
  Leptogenesis
  We propose a novel and minimal framework where a light scalar field can give
rise to dark matter (DM) self-interactions while enhancing the CP asymmetry
required for successful leptogenesis. The lightest among the right handed
neutrinos (RHN) introduced for generating light neutrino masses radiatively,
play the role of DM while the heavier two can play non-trivial roles in
generating DM relic as well as lepton asymmetry. While dark matter
self-interactions mediated by the singlet scalar can alleviate the small scale
issues of cold dark matter paradigm, the same scalar can give rise to new
one-loop decay processes of heavy RHN into standard model leptons providing an
enhanced contribution to CP asymmetry, even with sub-TeV scale RHN mass. The
thermally under-abundant relic of DM due to large annihilation rates into its
light mediator receives a late non-thermal contribution from a heavier RHN.
With only five new particles each having non-trivial roles in generating DM
relic and baryon asymmetry, the model can explain non-zero neutrino mass while
being verifiable at different experiments related to DM direct detection,
flavour physics and colliders.
