Large-scale galaxy correlations from the DESI first data release

Francesco Sylos Labini, Tibor Antal

A&A, Forthcoming article

Received: 26 November 2025 / Accepted: 04 February 2026

DOI: https://doi.org/10.1051/0004-6361/202558271

The spatial distribution of galaxies is a fundamental observable for probing the large-scale structure of the Universe. Accurately characterizing its statistical properties poses a significant challenge, as this distribution exhibits complex, highly inhomogeneous features and includes the largest structures ever detectedn the cosmos, representing one of the most compelling manifestations of complexity in nature. A key question, debated for decades (oncerns the scale at which the galaxy distribution can be considered statistically uniform. Determining this scale is esential for assessing whether the observed structures are compatible with current models of galaxy formation. Addressing this issue requires statistical methods that are free of strong assumptions and based on the most conservative hypotheses, in order to minimize luminosity-selection biases and finite-size effects.

The large statistics of the DESI samples also allowed us to demonstrate that finite-size e ects become significant as distance scale approaches the boundaries of the sample volumes. We consistently found that the distribution of density fluctuations follows a Gumbel distribution — characteristic of extreme-value statistics — rather than a Gaussian distribution, which would be expected for a spatially homogeneous field. These findings confirm and extend the trends previously observed in smaller redshift surveys, supporting the conclusion that the galaxy distribution does not undergo a transition
to spatial homogeneity within the probed scales, up to r=400 Mpc/h.