Testing gravity on large scales. The skewness of the galaxy distribution at z~1

TL;DR

This paper investigates the evolution of galaxy distribution skewness at redshifts 0.7 to 1.5, confirming gravitational instability predictions and emphasizing the role of non-linear galaxy biasing over 9 billion years.

Contribution

It provides observational evidence supporting gravitational instability theory and highlights the significance of non-linear biasing in galaxy distribution evolution.

Findings

Variance and skewness evolve consistently with perturbation theory

Supports gravitational instability paradigm over 9 Gyrs

Highlights importance of non-linear galaxy biasing

Abstract

We study the evolution of the low-order moments of the galaxy overdensity distribution over the redshift interval 0.7<z<1.5. We find that the variance and the normalized skewness evolve over this redshift interval in a way that is remarkably consistent with predictions of first- and second-order perturbation theory. This finding confirms the standard gravitational instability paradigm over nearly 9 Gyrs of cosmic time and demonstrates the importance of accounting for the non-linear component of galaxy biasing to avoid disagreement between theory and observations.