Dynamics of the quantum vacuum: Cosmology as relaxation to the
  equilibrium state
  The behavior of the gravitating vacuum energy density in an expanding
universe is discussed. A scenario is presented with a step-wise relaxation of
the vacuum energy density. The vacuum energy density moves from plateau to
plateau and follows, on average, the steadily decreasing matter energy density.
The current plateau with a small positive value of the vacuum energy density
(effective cosmological constant) may result from a still not equilibrated
contribution of the light massive neutrinos to the quantum vacuum.
