  Cosmological consequences of a coupling between massive neutrinos and dark
energy are investigated. In such models, the neutrino mass is a function of a
scalar field, which plays the role of dark energy. The background evolution, as
well as the evolution of cosmological perturbations is discussed. We find that
mass-varying neutrinos can leave a significant imprint on the anisotropies in
the cosmic microwave background radiation and even lead to a reduction of power
on large angular scales.
