Relaxing neutrino mass bounds by a running cosmological constant

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 us to largely evade current cosmological neutrino mass bounds and discuss how the scenario might be probed with the help of future large scale structure surveys and Planck data.