http://arxiv.org/abs/1611.02139
The homogeneity of matter distribution at large scales is a central assumption in the standard cosmological model. The case is testable though, thus no longer needs to be a principle, and indeed there have been claims that the distribution of galaxies is homogeneous at radius scales larger than 70 Mpc/h. Here we perform a test for homogeneity using the Sloan Digital Sky Survey Luminous Red Galaxies (LRG) sample by counting galaxies within a specified volume with the radius scale varying up to 300 Mpc/h. Our analysis differs from the previous ones in that we directly confront the large-scale structure data with the definition of spatial homogeneity by comparing the fluctuations of individual number counts with allowed ranges of the random distribution with homogeneity. The LRG sample shows much larger fluctuations of number counts than the random catalogs up to 300 Mpc/h scale, and even the average is located far outside the range allowed in the random distribution, which implies that the cosmological principle does not hold even at such large scales. The same analysis of mock galaxies derived from the N-body simulation, however, suggests that the LRG sample is consistent with the current paradigm of cosmology. Thus, we conclude that the cosmological principle is not in the observed sky and nor is demanded to be there by the standard cosmological world model. This reveals the nature of the cosmological principle adopted in the modern cosmology paradigm, and opens new field of research in theoretical cosmology.
C. Park, H. Hyun, H. Noh, et. al.
Tue, 8 Nov 16
66/75
Comments: 7 pages, 6 figures
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