A Generalized Cosmological Reduced Void Probability Distribution Function and Levy Index
Abstract
We use data from the Sloan Digital Sky Survey, the DEEP2 survey and numerical runs of the Gadget II code to analyze the distribution of cosmological voids in the universe similar to the model proposed by Mekjian.1 The general form of the Void Probability Function focuses on a scaling model inspired from percolation theory that gives an analytical form for the distribution function. For large redshifts the early universe was smooth and the probability function has a simple mathematical form that mimics the two point correlation results leading to a Zipf's Law probability distribution indicating an ever decreasing probability of larger and larger voids, we determine the Zipf form of the scaling power law for void frequency. As various large scale galactic structures emerge in a given simulation a number of relatively empty regions are isolated and characterized as voids based upon number counts in the associated volume. The number density of these regions is such that the universe has a large scale "sponge-like” appearance with voids of all scales permeating the field of observation, hinting at the existence of an underlying scaling law. For these data sets we examine the range of critical void probability function parameters that give rise to the best fit to the numerical and observational data. The resulting void probability functions are then used to determine the Levy index and the Fisher critical exponent within the context of a grand canonical ensemble analysis viewed as a percolation effect.
We wish to thank the Kentucky Space Grant Consortium for providing the NASA grant funding this research 1. Aram Z. Mekjian , Generalized statistical models of voids and hierarchical structure in cosmology, The Astrophysical Journal, 655: 1-10, 2007, arXiv:0712.1217- Publication:
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American Astronomical Society Meeting Abstracts #213
- Pub Date:
- January 2009
- Bibcode:
- 2009AAS...21348305S