Reconciling Planck with the local value of H0 in extended parameter space

The recent determination of the local value of the Hubble constant by Riess et al, 2016 (hereafterR16) is now3.3sigma higher than the value derived from the most recent CMB anisotropy dataprovided by the Planck satellite in aΛCDM model. Here we perform a combined analysis of thePlanck and R16 results in an extended parameter space, varying simultaneously12cosmologicalparameters instead of the usual6. We find that a phantom-like dark energy component, witheffective equation of statew=−1.29+0.15−0.12at68%c.l. can solve the current tension between thePlanck dataset and the R16 prior in an extendedΛCDM scenario. On the other hand, the neutrinoeffective number is fully compatible with standard expectations. This result is confirmed whenincluding cosmic shear data from the CFHTLenS survey and CMB lensing constraints from Planck.However, when BAO measurements are included we find that some of the tension with R16 remains,as also is the case when we include the supernova type Ia luminosity distances from the JLA catalog