Excess Clustering on Large Scales in the MegaZ DR7 Photometric Redshift
  Survey
  We observe a large excess of power in the statistical clustering of Luminous
Red Galaxies in the photometric SDSS galaxy sample called MegaZ DR7. This is
seen over the lowest multipoles in the angular power spectra C_{\ell} in four
equally spaced redshift bins between 0.45 < z < 0.65. However, it is most
prominent in the highest redshift band at ~ 4 sigma and it emerges at an
effective scale k ~ 0.01 h Mpc^{-1}. Given that MegaZ DR7 is the largest cosmic
volume galaxy survey to date (3.3 (Gpc h^{-1})^3) this implies an anomaly on
the largest physical scales probed by galaxies. Alternatively, this signature
could be a consequence of it appearing at the most systematically susceptible
redshift. There are several explanations for this excess power that range from
systematics to new physics. This could have important consequences for the next
generation of galaxy surveys or the LCDM model. We test the survey, data and
excess power, as well as possible origins.
