### Abstract

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 R^{3} 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 × 10^{7} h^{-3} Mpc^{3}) 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 language | English (US) |
---|---|

Pages (from-to) | 54-58 |

Number of pages | 5 |

Journal | Astrophysical Journal |

Volume | 624 |

Issue number | 1 I |

DOIs | |

State | Published - May 1 2005 |

### Fingerprint

### Keywords

- Cosmological parameters
- Cosmology: observations
- Galaxies: statistics
- Large-scale structure of universe
- Methods: statistical
- Surveys

### ASJC Scopus subject areas

- Space and Planetary Science

### Cite this

*Astrophysical Journal*,

*624*(1 I), 54-58. https://doi.org/10.1086/429084

**Cosmic homogeneity demonstrated with luminous red galaxies.** / Hogg, David W.; Eisenstein, Daniel J.; Blanton, Michael R.; Bahcall, Neta A.; Brinkmann, J.; Gunn, James E.; Schneider, Donald P.

Research output: Contribution to journal › Article

*Astrophysical Journal*, vol. 624, no. 1 I, pp. 54-58. https://doi.org/10.1086/429084

}

TY - JOUR

T1 - Cosmic homogeneity demonstrated with luminous red galaxies

AU - Hogg, David W.

AU - Eisenstein, Daniel J.

AU - Blanton, Michael R.

AU - Bahcall, Neta A.

AU - Brinkmann, J.

AU - Gunn, James E.

AU - Schneider, Donald P.

PY - 2005/5/1

Y1 - 2005/5/1

N2 - 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.

AB - 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.

KW - Cosmological parameters

KW - Cosmology: observations

KW - Galaxies: statistics

KW - Large-scale structure of universe

KW - Methods: statistical

KW - Surveys

UR - http://www.scopus.com/inward/record.url?scp=20344392642&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=20344392642&partnerID=8YFLogxK

U2 - 10.1086/429084

DO - 10.1086/429084

M3 - Article

VL - 624

SP - 54

EP - 58

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1 I

ER -