Testing gravitational physics by combining DESI DR1 and weak lensing datasets using the E_G estimator

TL;DR

This study combines multiple large-scale structure and weak lensing datasets to measure the E_G gravitational estimator across a wide redshift range, testing General Relativity's predictions within the standard cosmological model.

Contribution

It introduces a novel combined-probe analysis using DESI DR1 and existing weak lensing surveys to measure E_G at higher redshifts than previously possible, providing new constraints on GR.

Findings

Results are consistent with Planck cosmology predictions.

First E_G measurements at redshift z ~ 1.

Supports GR validity within current observational limits.

Abstract

The action of gravitational physics across space-time creates observable signatures in the behaviour of light and matter. We perform combined-probe studies using data from the Baryon Oscillation Spectroscopic Survey (BOSS) and Dark Energy Spectroscopic Instrument survey Data Release 1 (DESI-DR1), in combination with three existing weak lensing surveys, the Kilo-Degree Survey (KiDS), the Dark Energy Survey (DES), and the Hyper Suprime-Cam Survey (HSC), to test and constrain General Relativity (GR) in the context of the standard model of cosmology (LCDM). We focus on measuring the gravitational estimator statistic, E_G, which describes the relative amplitudes of weak gravitational lensing and galaxy velocities induced by a common set of overdensities. By comparing our amplitude measurements with their predicted scale- and redshift-dependence within the GR+LCDM model, we demonstrate that our results are consistent with the predictions of the Planck cosmology. The redshift span of the DESI dataset allows us to perform these E_G measurements at the highest redshifts achieved to date, z ~ 1.