  We propose a new solution to the origin of dark energy. We suggest that it
was created dynamically from the condensate of a singlet neutrino at a late
epoch of the early Universe through its effective self interaction. This
singlet neutrino is also the Dirac partner of one of the three observed
neutrinos, hence dark energy is related to neutrino mass. The onset of this
condensate formation in the early Universe is also related to matter density
and offers an explanation of the coincidence problem of why dark energy (70%)
and total matter (30%) are comparable at the present time. We demonstrate this
idea in a model of neutrino mass with (right-handed) singlet neutrinos and a
singlet scalar.
