Quasi-periodical features in the distribution of Luminous Red Galaxies
  A statistical analysis of radial distributions of Luminous Red Galaxies
(LRGs) from the Sloan Digital Sky Survey (SDSS DR7) catalogue within an
interval $0.16 \leq z \leq 0.47$ is carried out. We found that the radial
distribution of $\sim$ 106,000 LRGs incorporates a few quasi-periodical
components relatively to a variable $\eta$, dimensionless line-of-sight
comoving distance calculated for the $\Lambda$CDM cosmological model. The most
significant peaks of the power spectra are obtained for two close periodicities
corresponding to the spatial comoving scales $(135 \pm 12) h^{-1}$ Mpc and
$(101 \pm 6)h^{-1}$ Mpc. The latter one is dominant and consistent with the
characteristic scale of the baryon acoustic oscillations. We analyse also the
radial distributions of two other selected LRG samples: $\sim$ 33,400 bright
LRGs ($-23.2 < M \leq -21.8$) and $\sim$ 60,300 all LRGs within a rectangle
region on the sky, and show differences of the quasi-periodical features
characteristic for different samples. Being confirmed the results would allow
to give preference of the spatial against temporal models which could explain
the quasi-periodicities discussed here. As a caveat we show that estimations of
the significance levels of the peaks strongly depend on a smoothed radial
function (trend) as well as characteristics of random fluctuations.
