  We use general arguments to examine the energy scales for which a quantum
coherent description of gravitating quantum energy units is necessary. The
cosmological dark energy density is expected to decouple from the
Friedman-Lemaitre energy density when the Friedman-Robertson-Walker scale
expansion becomes sub-luminal, at which time the usual microscopic interactions
of relativistic quantum mechanics (QED, QCD, etc) open new degrees of freedom.
The expected gravitational vacuum energy density at that scale would be
expected to freeze out due to the loss of gravitational coherence. We define
the vacuum energy which generates this cosmological constant to be that of a
zero temperature Bose condensate at this gravitational de-coherence scale.
Since the arguments presented involve primarily counting of degrees of freedom,
we expect the statistical equilibrium states of causally disconnected regions
of space to be independently identical. Thus, there is no luminal "horizon"
problem associated with the lack of causal influences between spatially
separated regions in this approach. The scale of the amplitude of fluctuations
produced during de-coherence of cosmological vacuum energy are found to evolve
to values consistent with those observed in cosmic microwave background
radiation and galactic clustering.
