Cosmic homogeneity demonstrated with luminous red galaxies

David W. Hogg, Daniel J. Eisenstein, Michael R. Blanton, Neta A. Bahcall, J. Brinkmann, James E. Gunn, Donald P. Schneider

Research output: Contribution to journalArticlepeer-review

207 Scopus citations


We test the homogeneity of the universe at z ∼ 0.3 with the luminous red galaxy (LRG) spectroscopic sample of the Sloan Digital Sky Survey. First, the mean number N(R) of LRGs within completely surveyed LRG-centered spheres of comoving radius R is shown to be proportional to R3 at radii greater than R ∼ 70 h-1 Mpc. The test has the virtue that it does not rely on the assumption that the LRG sample has a finite mean density; its results show, however, that there is such a mean density. Second, the survey sky area is divided into 10 disjoint solid angular regions, and the fractional rms density variations of the LRG sample in the redshift range 0.2 < z < 0.35 among these (∼2 × 107 h-3 Mpc3) regions is found to be 7% of the mean density. This variance is consistent with typical biased ACDM models and puts very strong constraints on the quality of SDSS photometric calibration.

Original languageEnglish (US)
Pages (from-to)54-58
Number of pages5
JournalAstrophysical Journal
Issue number1 I
StatePublished - May 1 2005

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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