Testing gravity using galaxy-galaxy lensing and clustering amplitudes in
  KiDS-1000, BOSS and 2dFLenS
  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 dz = 0.1 tomographic
redshift bins in the range 0.2 < z < 0.7, on projected scales up to 100 Mpc/h.
The scale-independence and redshift-dependence of these measurements are
consistent with the theoretical expectation of general relativity in a Universe
with matter density Omega_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 compare the performance
of angular and projected galaxy-galaxy lensing statistics.
