Cosmic homogeneity: a spectroscopic and model-independent measurement

Abstract

Cosmology relies on the Cosmological Principle, i.e., the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this Letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale ${\theta }_{\mathrm{h}}$. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that ${\theta }_{\mathrm{h}}$ varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.

5 pages, 2 figures, Version accepted by MNRAS

References in corpus (6)

• J-PAS: The Javalambre-Physics of the Accelerated Universe Astrophysical Survey
• Homogeneity and isotropy in the 2MASS Photometric Redshift catalogue
• Anisotropy in the all-sky distribution of galaxy morphological types
• North-South non-Gaussian asymmetry in PLANCK CMB maps
• Asymmetry in the reconstructed deceleration parameter
• An information theory based search for homogeneity on the largest accessible scale

Cited by in corpus (3)

• The angular scale of homogeneity in the Local Universe with the SDSS blue galaxies
• Measuring the Homogeneity of the Universe Using Polarization Drift
• Mapping Poincaré gauge cosmology to Horndeski theory for emergent dark energy