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 N-body simulations. Copyright (C) EPLA, 2009

ABSENCE OF SELF-AVERAGING AND OF HOMOGENEITY IN THE LARGE SCALE GALAXY DISTRIBUTION / F., SYLOS LABINI; N. L., Vasilyev; Pietronero, Luciano; Y. V., Baryshev. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - STAMPA. - 86(4):(2009), pp. 49001-p1-49001-p6. [10.1209/0295-5075/86/49001]

ABSENCE OF SELF-AVERAGING AND OF HOMOGENEITY IN THE LARGE SCALE GALAXY DISTRIBUTION

PIETRONERO, Luciano;
2009

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 N-body simulations. Copyright (C) EPLA, 2009
2009
01 Pubblicazione su rivista::01a Articolo in rivista
ABSENCE OF SELF-AVERAGING AND OF HOMOGENEITY IN THE LARGE SCALE GALAXY DISTRIBUTION / F., SYLOS LABINI; N. L., Vasilyev; Pietronero, Luciano; Y. V., Baryshev. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - STAMPA. - 86(4):(2009), pp. 49001-p1-49001-p6. [10.1209/0295-5075/86/49001]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1773
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