Experiments and astronomical observations may eventually show that there are comparable energy densities in the present universe from neutrino mass and from an effective cosmological constant, each at the level of a few per cent of the closure density, and similar to the empirical energy density in baryons. We consider the possibility that the cause of such a coincidence is related to a spontaneous breakdown of CP invariance characterized by a cosmological energy scale. Such a spontaneous breakdown can give rise to a neutrino-antineutrino asymmetry just prior to the time of electroweak symmetry breaking. CP noninvariance can also be at the origin of neutrino mass, through the square of a vacuum expectation value F_b~2, for a pseudoscalar field b. The exchange of energy between a specific residual vacuum energy density which involves F_b~2, and neutrino mass, is considered to have an oscillatory behavior in time. A microphysical-time variation of neutrino mass (squared) can have consequences for present neutrino flavor-oscillation experiments. We give detailed examples of the effects.
展开▼
