Full-shape cosmology analysis of SDSS-III BOSS galaxy power spectrum
  using emulator-based halo model: a $5\%$ determination of $\sigma_8$
  We present the results obtained from the full-shape cosmology analysis of the
redshift-space power spectra for 4 galaxy samples of the SDSS-III BOSS DR12
galaxy catalog over $0.2 < z < 0.75$. For the theoretical template, we use an
emulator that was built from an ensemble set of $N$-body simulations, which
enables fast and accurate computation of the redshift-space power spectrum of
halos. Combining with the halo occupation distribution to model the halo-galaxy
connection, we can compute the redshift-space power spectrum of BOSS-like
galaxies in the flat $\Lambda$CDM cosmology. In our cosmology inference, we use
the power spectrum monopole, quadrupole and hexadecapole and include 7 nuisance
parameters to model uncertainties in the halo-galaxy connection for each galaxy
sample, but do not use any information on the abundance of galaxies. We
demonstrate a validation of our analysis pipeline using the mock catalogs of
BOSS-like galaxies, generated using different recipes of the halo-galaxy
connection and including the assembly bias effect. Assuming weak priors on
cosmological parameters, except for $\Omega_{\rm b}h^2$ and $n_{\rm s}$, we
show that our model well reproduces the BOSS power spectra. Including the power
spectrum information up to $k_{\rm max}=0.25\,h{\rm Mpc}^{-1}$, we find
$\Omega_\mathrm{m}=0.301^{+0.012}_{-0.011}$, $H_0=68.2 \pm
1.4~\mathrm{km\,s}^{-1}\mathrm{Mpc}^{-1}$, and
$\sigma_8=0.786^{+0.036}_{-0.037}$, for the mode and 68\% credible interval,
after marginalization over nuisance parameters. We find little improvement in
the cosmological parameters beyond a maximum wavelength $k_{\rm max}\simeq
0.2\,h\,{\rm Mpc}^{-1}$ due to the shot noise domination and marginalization of
the halo-galaxy connection parameters. Our results are consistent with the
Planck CMB results within $1\sigma$ statistical uncertainties.
