  We explore the dynamics of neutrinos in a vacuum dominated cosmology. First
we show that such a geometry will induce a phase change in the eigenstates of a
massive neutrino and we calculate the phase change. We also calculate the delay
in the neutrino flight times in this geometry. Applying our results to the
presently observed background vacuum energy density, we find that for neutrino
sources further than $1.5 Gpc$ away both effects become non-trivial, being of
the order of the standard relativistic corrections. Such sources are within the
obsevable Hubble Deep Field. The results which are theoretically interesting
are also potentially useful, in the future, as detection techniques improve.
For example such effects on neutrinos from distant sources like supernovae
could be used, in an independent method alternative to standard candles, to
constrain the dark energy density and the deceleration parameter. The
discussion is extended to investigate Caianiello's inertial or maximal
acceleration (MA) effects of such a vacuum dominated spacetime on neutrino
oscillations. Assuming that the MA phenomenon exists, we find that its form as
generated by the presently observed vacuum energy density would still have
little or no measurable effect on neutrino phase evolution.
