Constraints on f(R) theory and Galileons from the latest data of galaxy
  redshift surveys
  The growth rate of matter density perturbations has been measured from
redshift-space distortion (RSD) in the galaxy power spectrum. We constrain the
model parameter space for representative modified gravity models to explain the
dark energy problem, by using the recent data of f_m(z)sigma_8(z) at the
redshifts z = 0.06--0.8 measured by WiggleZ, SDSS LRG, BOSS, and 6dFGRS. We
first test the Hu-Sawicki's f(R) dark energy model, and find that only the
parameter region close to the standard Lambda Cold Dark Matter (Lambda-CDM)
model is allowed (lambda > 12 and 5 for n = 1.5 and 2, respectively, at 95%
CL). We then investigate the covariant Galileon model and show that the
parameter space consistent with the background expansion history is excluded by
the RSD data at more than 10 sigma because of the too large growth rate
predicted by the theory. Finally, we consider the extended Galileon scenario,
and we find that, in contrast to the covariant Galileon, there is a model
parameter space for a tracker solution that is consistent with the RSD data
within a 2 sigma level.
