Observational evidence of fractality in the large-scale distribution of galaxies

TL;DR

This study provides observational evidence that the large-scale distribution of galaxies exhibits fractal properties with a dimension around 2 below 20 Mpc, indicating non-homogeneity at these scales.

Contribution

It introduces a novel graph-based method to estimate the fractal dimension of galaxy distributions and confirms fractality using two different approaches.

Findings

Fractal dimension D ≈ 2 below 20 Mpc scale.

Galaxy distribution is non-homogeneous at certain scales.

Validates previous findings with new methods.

Abstract

Using a sample of 133 991 galaxies distributed in the sky region $100^{\circ} <\alpha<270^{\circ}$ and $7^{\circ}<\delta<65^{\circ}$, extracted from the SDSS NASA/AMES Value Added Galaxy Catalog (AMES-VAGC), we estimate the fractal dimension using two different methods. First, using an algorithm to estimate the correlation dimension. The second method, in a novel approach, creates a graph from the data and estimates the graph dimension purely from connectivity information. In both methods we found a dimension $D\approx 2$ in scales below 20 Mpc, which agrees with previous works. This result shows the non-homogeneity of galaxies distribution at certain scales.