Cosmic homogeneity: a spectroscopic and model-independent measurement

Understand

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 $\theta_{\rm h}$.