New constraints on interacting dark energy from Planck experiment

We present new constraints on interacting dark energy from the recent measurements of the Cosmic Microwave Background Anisotropies from the Planck satellite experiment. We show that an interacting dark-energy model is compatible with the Planck measurements, deriving a weak bound on the dark matter-dark energy coupling parameter xi = -0.49(-0.31)(+0.19) at 68% c.l.. Moreover if Planck data are fitted to an interacting dark energy scenario, the constraint on the Hubble constant is relaxed to H-0 = 72.1(-2.3)(+3.2) km/s/Mpc, solving the tension with the Hubble Space Telescope measurement. We find that a combined Planck+HST analysis provides significant evidence for coupled dark energy finding a non-zero value for the coupling parameter xi, with -0.90 < xi < -0.22 at 95% c.l.