Skewness consistency relation in large-scale structure and test of gravity theory

TL;DR

This paper proposes using the skewness of galaxy density fluctuations as a novel test for gravity theories, deriving a consistency relation that can distinguish general relativity from modified gravity models.

Contribution

It introduces a new skewness-based consistency relation for testing gravity theories, extending analysis from real to redshift space.

Findings

Derived the skewness consistency relation for real space

Extended the relation to redshift space

Provided a method to test gravity theories using galaxy data

Abstract

We investigate the skewness of galaxy number density fluctuations as a possible probe to test gravity theories. We find that the specific linear combination of the skewness parameters corresponds to the coefficients of the second-order kernels of the density contrast, which can be regarded as the consistency relation and used as a test of general relativity and modified gravity theories. We also extend the analysis of the skewness parameters from real space to redshift space and derive the redshift-space skewness consistency relation.