The clustering of galaxies in the SDSS-III Baryon Oscillation
  Spectroscopic Survey: cosmological constraints from the full shape of the
  clustering wedges
  We explore the cosmological implications of the clustering wedges, xi_perp(s)
and xi_para(s), of the CMASS Data Release 9 (DR9) sample of the Baryon
Oscillation Spectroscopic Survey (BOSS). These clustering wedges are defined by
averaging the full two-dimensional correlation function, xi(mu,s), over the
ranges 0<mu<0.5 and 0.5<mu<1, respectively. These measurements allow us to
constrain the parameter combinations D_A(z)/r_s(z_d)=9.03 +- 0.21 and
cz/(r_s(z_d)H(z)) = 12.14 +- 0.43 at the mean redsfhit of the sample, z=0.57.
We combine the information from the clustering wedges with recent measurements
of CMB, BAO and type Ia supernovae to obtain constraints on the cosmological
parameters of the standard LCDM model and a number of potential extensions. The
information encoded in the clustering wedges is most useful when the dark
energy equation of state is allowed to deviate from its standard LCDM value.
The combination of all datasets shows no evidence of a deviation from a
constant dark energy equation of state, in which case we find w_DE = -1.013 +-
0.064, in complete agreement with a cosmological constant. We explore potential
deviations from general relativity by constraining the growth rate f(z)=d ln
D(a)/ d ln a, in which case the combination of the CMASS clustering wedges with
CMB data implies f(z=0.57)=0.719 +- 0.094, in accordance with the predictions
of GR. Our results clearly illustrate the additional constraining power of
anisotropic clustering measurements with respect to that of angle-averaged
quantities.
