Absolute neutrino mass phenomenology

Four approaches to the determination of absolute neutrino mass below 1 eV seem plausible: measurement of the zero-neutrino double beta decay rate, of the tritium decay end-point spectrum, of the cosmic ray spectrum above the GZK cutoff, and of the power spectrum governing the CMB and large scale structure. The first two approaches are sensitive to the mass eigenstates coupling to the electron neutrino, whereas the latter two are sensitive to the heavy components of the cosmic neutrino background. All mass eigenstates axe related by the deltam(2,)s inferred from neutrino oscillation data. Consequently, the four approaches are cross-correlated with each other. We examine these correlations, and note that they will be invaluable in truly establishing the absolute neutrio mass scale, and the existence of the cosmic neutrino background.