The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: measurements of the growth of structure and expansion rate atz= 0.57 from anisotropic clustering

We analyze the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of 264, 283 galaxies in the redshift range 0. 43 0. 57, and when combined imply Ω_Λ = 0. 74 +/- 0. 016, independent of the Universe's evolution at z<0. 57. In our companion paper (Samushia et al. prep), we explore further cosmological implications of these observations.