  We establish an indirect link between relic neutrinos and the dark energy
sector which originates from the vacuum energy contributions of the neutrino
quantum fields. Via renormalization group effects they induce a running of the
cosmological constant with time which dynamically influences the evolution of
the cosmic neutrino background. We demonstrate that the resulting reduction of
the relic neutrino abundance allows to largely evade current cosmological
neutrino mass bounds and discuss how the scenario might be probed by the help
of future large scale structure surveys and Planck data.
