Electroweak vacuum stability in presence of singlet scalar dark matter in TeV scale seesaw models

We consider singlet extensions of the standard model, both in the fermion and in the scalar sector, to account for the generation of neutrino mass at the TeV scale and the existence of dark matter, respectively. For the neutrino sector we consider models with extra singlet fermions that can generate neutrino mass via the so-called inverse or linear seesaw mechanism, whereas a singlet scalar is introduced as the candidate for dark matter. We show that although these two sectors are disconnected at low energy, the coupling constants of both the sectors get correlated at the high-energy scale by the constraints coming from the perturbativity and stability/metastability of the electroweak vacuum. The singlet fermions try to destabilize the electroweak vacuum while the singlet scalar aids the stability. As an upshot, the electroweak vacuum may attain absolute stability even up to the Planck scale for suitable values of the parameters. We delineate the parameter space for the singlet fermion and the scalar couplings for which the electroweak vacuum remains stable/metastable and at the same time gives the correct relic density and neutrino masses and mixing angles as observed.