Testing gravity using galaxy-galaxy lensing and clustering amplitudes in KiDS-1000, BOSS, and 2dFLenS

Abstract

The physics of gravity on cosmological scales affects both the rate of assembly of large-scale structure and the gravitational lensing ofbackground light through this cosmic web. By comparing the amplitude of these different observational signatures, we can constructtests that can distinguish general relativity from its potential modifications. We used the latest weak gravitational lensing dataset fromthe Kilo-Degree Survey, KiDS-1000, in conjunction with overlapping galaxy spectroscopic redshift surveys, BOSS and 2dFLenS, toperform the most precise existing amplitude-ratio test. We measured the associatedEGstatistic with 15−20% errors in five∆z=0.1tomographic redshift bins in the range 0.2<z<0.7 on projected scales up to 100h−1Mpc. The scale-independence and redshift-dependence of these measurements are consistent with the theoretical expectation of general relativity in a Universe with matterdensityΩm=0.27 +- 0.04. We demonstrate that our results are robust against different analysis choices, including schemes forcorrecting the effects of source photometric redshift errors, and we compare the performance of angular and projected galaxy-galaxylensing statistics.