Metastable dark energy
  We build a model of metastable dark energy, in which the observed vacuum
energy is the value of the scalar potential at the false vacuum. The scalar
potential is given by a sum of even self-interactions up to order six. The
deviation from the Minkowski vacuum is due to a term suppressed by the Planck
scale. The decay time of the metastable vacuum can easily accommodate a mean
life time compatible with the age of the universe. The metastable dark energy
is also embedded into a model with $SU(2)_R$ symmetry. The dark energy doublet
and the dark matter doublet naturally interact with each other. A three-body
decay of the dark energy particle into (cold and warm) dark matter can be as
long as large fraction of the age of the universe, if the mediator is massive
enough, the lower bound being at intermediate energy level some orders below
the grand unification scale. Such a decay shows a different form of interaction
between dark matter and dark energy, and the model opens a new window to
investigate the dark sector from the point-of-view of particle physics.
