The power spectrum and bispectrum of SDSS DR11 BOSS galaxies I: bias and gravity

We analyse the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS Data Release 11 sample, which consists of $690 827$ galaxies in the redshift range 0.43 < z < 0.70 and has a sky coverage of 8498 deg2 corresponding to an effective volume of ˜ 6 Gpc3. We fit the Fourier space statistics, the power spectrum and bispectrum monopoles to measure the linear and quadratic bias parameters, b1 and b2, for a non-linear non-local bias model, the growth of structure parameter f and the amplitude of dark matter density fluctuations parametrized by sigma8. We obtain b1(zeff)1.40sigma8(zeff) = 1.672 ± 0.060 and b_2^{0.30}(z_eff)sigma _8(z_eff)=0.579± 0.082 at the effective redshift of the survey, zeff = 0.57. The main cosmological result is the constraint on the combination f 0.43(zeff)sigma8(zeff) = 0.582 ± 0.084, which is complementary to fsigma8 constraints obtained from two-point redshift-space distortion analyses. A less conservative analysis yields f 0.43(zeff)sigma8(zeff) = 0.584 ± 0.051. We ensure that our result is robust by performing detailed systematic tests using a large suite of survey galaxy mock catalogues and N-body simulations. The constraints on f 0.43sigma8 are useful for setting additional constraints on neutrino mass, gravity, curvature as well as the number of neutrino species from galaxy surveys analyses (as presented in a companion paper).