2021/03/31 by Biswajit Pandey, Suman Sarkar
Physics and Astronomy · #Astronomy and Astrophysical Research #COSMIC cancer database #Entropy (arrow of time) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Homogeneity (statistics) #Homogeneous #Poisson distribution #Rényi entropy #Statistical Mechanics and Entropy #Surface brightness fluctuation #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2021/07/019
16 pages, 4 figures, 1 table, Substantial revision, Accepted for publication in JCAP
openalex created_date 2021/03/29 · arxiv created 2021/06/20 · openalex publication_date 2021/07/01 · arxiv updated 2021/07/21 · openalex updated_date 2026/08/05
Abstract We analyze a set of volume limited sample of galaxies from the SDSS to study the issue of cosmic homogeneity. We use the Renyi entropy of different order to probe the inhomogeneties present in the galaxy distributions. We also calculate the Renyi diveregence to quantify the deviations of the galaxy distribution from a homogeneous Poisson distribution on different length scales. We separately carry out the analysis using the overlapping spheres and the independent voxels. Our analysis suggests that the scale of homogeneity is underestimated in the smaller galaxy samples due to the suppression of inhomogeneities by the overlapping of the measuring speheres. We find that an analysis with the independent voxels and/or use of a significantly larger galaxy sample can help to circumvent or mitigate this problem. Combining the results from these analyses, we find that the galaxy distribution in the SDSS becomes homogeneous on a length scale beyond 140 h -1 Mpc.