2019/05/31 by Carlos A. P. Bengaly, Carlos A.P. Bengaly, Roy Maartens +2 · 1 citation
Physics and Astronomy · #Cosmic variance #Cosmological principle #Cosmology and Gravitation Theories #Dark energy #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Homogeneous #Isotropy #Sky #Universe #Variance (accounting) #astro-ph.CO #astro-ph.GA #gr-qc
paper · pdf · doi:10.1088/1475-7516/2019/09/025
published as JCAP09(2019)025 · 7 pages, 3 figures. To appear in JCAP
openalex created_date 2019/06/07 · arxiv created 2019/08/26 · openalex publication_date 2019/09/13 · arxiv updated 2019/09/16 · openalex updated_date 2026/08/05
The Cosmological Principle states that the Universe is statistically isotropic and homogeneous on large scales. In particular, this implies statistical isotropy in the galaxy distribution, after removal of a dipole anisotropy due to the observer's motion. We test this hypothesis with number count maps from the NVSS radio catalogue. We use a local variance estimator based on patches of different angular radii across the sky and compare the source count variance between and within these patches. In order to assess the statistical significance of our results, we simulate radio maps with the NVSS specifications and mask. We conclude that the NVSS data is consistent with statistical isotropy.