Title: "Cosmological Constant through decoherence?"
In a publication of 2002, J. Yokoyama argued that the cosmological
constant vanishes in the true ground state of the universe.
The small vacuumlike energy density which we observe can be explained
in a theory with two or more localized vacua.
In the context of decoherence one can explain the localization of the
cosmological constant in one localized minima.
Interaction with environment will reduce the tunneling rate and suppress
the nondiagonal elements of the density matrix.