Towards a solution of the cosmological constant problem
  The standard model of elementary particle physics and the theory of general
relativity can be extended by the introduction of a vacuum variable which is
responsible for the near vanishing of the present cosmological constant (vacuum
energy density). The explicit realization of this vacuum variable can be via a
three-form gauge field, an aether-type velocity field, or any other field
appropriate for the description of the equilibrium state corresponding to the
Lorentz-invariant quantum vacuum. The extended theory has, without fine-tuning,
a Minkowski-type solution of the field equations with spacetime-independent
fields and provides, therefore, a possible solution of the main cosmological
constant problem.
