A 2.5% measurement of the growth rate from small-scale redshift space
  clustering of SDSS-III CMASS galaxies
  We perform the first fit to the anisotropic clustering of SDSS-III CMASS DR10
galaxies on scales of ~ 0.8 - 32 Mpc/h. A standard halo occupation distribution
model evaluated near the best fit Planck LCDM cosmology provides a good fit to
the observed anisotropic clustering, and implies a normalization for the
peculiar velocity field of M ~ 2 x 10^13 Msun/h halos of f*sigma8(z=0.57) =
0.450 +/- 0.011. Since this constraint includes both quasi-linear and
non-linear scales, it should severely constrain modified gravity models that
enhance pairwise infall velocities on these scales. Though model dependent, our
measurement represents a factor of 2.5 improvement in precision over the
analysis of DR11 on large scales, f*sigma8(z=0.57) = 0.447 +/- 0.028, and is
the tightest single constraint on the growth rate of cosmic structure to date.
Our measurement is consistent with the Planck LCDM prediction of 0.480 +/-
0.010 at the ~1.9 sigma level. Assuming a halo mass function evaluated at the
best fit Planck cosmology, we also find that 10% of CMASS galaxies are
satellites in halos of mass M ~ 6 x 10^13 Msun/h. While none of our tests and
model generalizations indicate systematic errors due to an insufficiently
detailed model of the galaxy-halo connection, the precision of these first
results warrant further investigation into the modeling uncertainties and
degeneracies with cosmological parameters.
