Abstract
The precision of the cosmological data allows us to accurately approximate the predictions for cosmological observables by Taylor expanding up to a low order the dependence on the cosmological parameters around a reference cosmology. By applying this observation to the redshift-space one-loop galaxy power spectrum of the Effective Field Theory of Large-Scale Structure, we analyze the BOSS DR12 data by scanning over all the parameters of ΛCDM cosmology with massive neutrinos. We impose several sets of priors, the widest of which is just a Big Bang Nucleosynthesis prior on the current fractional energy density of baryons, Ωb h2, and a bound on the sum of neutrino masses to be less than 0.9 eV. In this case we measure the primordial amplitude of the power spectrum, As, the abundance of matter, Ωm, the Hubble parameter, H0, and the tilt of the primordial power spectrum, ns, to about 19%, 5.7%, 2.2% and 7.3% respectively, obtaining ln (1010As)=2.91± 0.19, Ωm=0.314± 0.018, H0=68.7± 1.5 km/(s Mpc) and ns=0.979± 0.071 at 68% confidence level. A public code is released with this preprint.