Absence of self-averaging and of homogeneity in the large scale galaxy distribution

Abstract

The properties of the galaxy distribution at large scales are usually studied using statistics which are assumed to be self-averaging inside a given sample. We present a new analysis able to quantitatively map galaxy large scale structures while testing for the stability of average statistical quantities in different sample regions. We find that the newest samples of the Sloan Digital Sky Survey provide unambiguous evidence that galaxy structures correspond to large amplitude density fluctuations at all scales limited only by sample sizes. The two-point correlations properties are self-averaging up to approximately 30 Mpc/h and are characterized by a fractal dimension D=2.1 +- 0.1. Then at all larger scales probed density fluctuations are too large in amplitude and too extended in space to be self-averaging inside the considered volumes. These inhomogeneities are compatible with a continuation of fractal correlations but incompatible with: (i) a homogeneity scale smaller than 100 Mpc/h, (ii) predictions of standard theoretical models, (iii) mock galaxy catalogs generated from cosmological Nbody simuations.

6 pages with 4 figures. Some changes to match the accepted version. To be published in Europhysics Letters (May 2009)

References in corpus (6)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• K-corrections and filter transformations in the ultraviolet, optical, and near infrared
• Exact solution to the averaging problem in cosmology
• Power law correlations in galaxy distribution and finite volume effects from the Sloan Digital Sky Survey Data Release Four
• Persistent fluctuations in the distribution of galaxies from the Two degree Field Galaxy Redshift Survey
• Extension and estimation of correlations in Cold Dark Matter models

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