  The recently published cosmological bound on the absolute neutrino masses
obtained from the Wilkinson Microwave Anisotropy Probe (WMAP) data has
important consequences for neutrino experiments and models. Taken at face
value, the new bound excludes the determination of the absolute neutrino mass
in the KATRIN experiment and disfavors a neutrino oscillation interpretation of
the LSND experiment. Combined with the KamLAND and Super-K data, the WMAP bound
defines an accessible range for the neutrinoless double beta decay amplitude.
The bound also impacts the Z-burst annihilation mechanism for resonant
generation of extreme-energy cosmic rays on the cosmic neutrino background in
two ways: it constrains the local overdensity of neutrino dark matter which is
not helpful, but it also limits the resonant energy to a favorable range. In
R-parity violating SUSY models neutrino masses are generated by trilinear and
bilinear lepton number violating couplings. The WMAP result improves the
constraints on these couplings over their existing values by an order of
magnitude.
