Testing gravity using galaxy-galaxy lensing and clustering amplitudes in KiDS-1000, BOSS, and 2dFLenS
Chris Blake, Alexandra Amon, Marika Asgari, Maciej Bilicki, Andrej Dvornik, Thomas Erben, Benjamin Giblin, Karl Glazebrook, Catherine Heymans, Hendrik Hildebrandt, Benjamin Joachimi, Shahab Joudaki, Arun Kannawadi, Konrad Kuijken, Chris Lidman, David Parkinson, HuanYuan Shan, Tilman Tröster, Jan Luca van den Busch, Christian Wolf, Angus H. Wright
Abstract
The physics of gravity on cosmological scales affects both the rate of assembly of large-scale structure and the gravitational lensing of background light through this cosmic web. By comparing the amplitude of these different observational signatures, we can construct tests that can distinguish general relativity from its potential modifications. We used the latest weak gravitational lensing dataset from the Kilo-Degree Survey, KiDS-1000, in conjunction with overlapping galaxy spectroscopic redshift surveys, BOSS and 2dFLenS, to perform the most precise existing amplitude-ratio test. We measured the associated E G statistic with 15 − 20% errors in five Δ z = 0.1 tomographic redshift bins in the range 0.2 < z < 0.7 on projected scales up to 100 h −1 Mpc. The scale-independence and redshift-dependence of these measurements are consistent with the theoretical expectation of general relativity in a Universe with matter density Ω m = 0.27 ± 0.04. We demonstrate that our results are robust against different analysis choices, including schemes for correcting the effects of source photometric redshift errors, and we compare the performance of angular and projected galaxy-galaxy lensing statistics.