Testing General Relativity with Cosmological Large Scale Structure

TL;DR

This paper explores methods to test Einstein's equations using cosmological large scale structure data, emphasizing the potential of analyzing fluctuations in energy-momentum and metric through galaxy counts, intensity mapping, and cosmic shear.

Contribution

It demonstrates how to improve tests of Einstein's equations by incorporating fluctuations in both energy-momentum tensor and metric, beyond the homogeneous universe approximation.

Findings

Current observations haven't fully tested Einstein's equations in the homogeneous universe.

Considering fluctuations enhances the ability to test Einstein's equations.

Examples include galaxy counts, intensity mapping, and cosmic shear.

Abstract

In this paper I investigate the possibility to test Einstein's equations with observations of cosmological large scale structure. I first show that we have not tested the equations in observations concerning only the homogeneous and isotropic Universe. I then show with several examples how we can do better when considering the fluctuations of both, the energy momentum tensor and the metric. This is illustrated with galaxy number counts, intensity mapping and cosmic shear, three examples that are by no means exhaustive.