Dark energy, scalar singlet dark matter and the Higgs portal
  One of the simplest extensions of the Standard Model (SM) comprises the
inclusion of a massive real scalar field, neutral under the SM gauge groups, to
be a dark matter candidate. The addition of a dimension-six term into the
potential of the scalar dark matter enables the appearance of a false vacuum
that describes the cosmic acceleration. We show that the running of the singlet
self-interaction and the Higgs portal coupling differs from the standard scalar
singlet dark matter model. If we maintain a positive quartic coupling, it is
also possible to describe the accelerated expansion of the Universe through a
false vacuum with the addition of a dimension-eight interaction term. In this
case, where the potential remains bounded from below at low energies, the false
vacuum decay is highly suppressed.
