What can we learn from higher multipole power spectra of galaxy
  distribution in redshift space?
  We investigate a potential of the higher multipole power spectra of the
galaxy distribution in redshift space as a cosmological probe on halo scales.
Based on the fact that a halo model explains well the multipole power spectra
of the luminous red galaxy (LRG) sample in the Sloan Digital Sky Survey (SDSS),
we focus our investigation on the random motions of the satellite LRGs that
determine the higher multipole spectra at large wavenumbers. We show that our
theoretical model fits the higher multipole spectra at large wave numbers from
N-body numerical simulations and we apply these results for testing the gravity
theory and the velocity structure of galaxies on the halo scales. In this
analysis, we use the multipole spectra P_4(k) and P_6(k) on the small scales of
the range of wavenumber 0.3<k/[h{Mpc}^{-1}]<0.6, which is in contrast to the
usual method of testing gravity by targeting the linear growth rate on very
large scales. We demonstrate that our method could be useful for testing
gravity on the halo scales.
