We obtain constraints on cosmological parameters from the spherically averaged redshift-space correlation function of the CMASS Data Release 9 ( DR9 ) sample of the Baryonic Oscillation Spectroscopic Survey ( BOSS ) .
We combine this information with additional data from recent CMB , SN and BAO measurements .
Our results show no significant evidence of deviations from the standard flat- \Lambda CDM model , whose basic parameters can be specified by \Omega _ { m } = 0.285 \pm 0.009 , 100 \Omega _ { b } = 4.59 \pm 0.09 , n _ { s } = 0.961 \pm 0.009 , H _ { 0 } = 69.4 \pm 0.8 { km } { s } ^ { -1 } { Mpc } ^ { -1 } and \sigma _ { 8 } = 0.80 \pm 0.02 .
The CMB+CMASS combination sets tight constraints on the curvature of the Universe , with \Omega _ { k } = -0.0043 \pm 0.0049 , and the tensor-to-scalar amplitude ratio , for which we find r < 0.16 at the 95 per cent confidence level ( CL ) .
These data show a clear signature of a deviation from scale-invariance also in the presence of tensor modes , with n _ { s } < 1 at the 99.7 per cent CL .
We derive constraints on the fraction of massive neutrinos of f _ { \nu } < 0.049 ( 95 per cent CL ) , implying a limit of \sum m _ { \nu } < 0.51 { eV } .
We find no signature of a deviation from a cosmological constant from the combination of all datasets , with a constraint of w _ { DE } = -1.033 \pm 0.073 when this parameter is assumed time-independent , and no evidence of a departure from this value when it is allowed to evolve as w _ { DE } ( a ) = w _ { 0 } + w _ { a } ( 1 - a ) .
The achieved accuracy on our cosmological constraints is a clear demonstration of the constraining power of current cosmological observations .