  The unknown nature of dark energy motivates continued cosmological tests of
large-scale gravitational physics. We present a new consistency check based on
the relative amplitude of non-relativistic galaxy peculiar motions, measured
via redshift-space distortion, and the relativistic deflection of light by
those same galaxies traced by galaxy-galaxy lensing. We take advantage of the
latest generation of deep, overlapping imaging and spectroscopic datasets,
combining the Red Cluster Sequence Lensing Survey (RCSLenS), the
Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS), the WiggleZ Dark
Energy Survey and the Baryon Oscillation Spectroscopic Survey (BOSS). We
quantify the results using the "gravitational slip" statistic E_G, which we
estimate as 0.48 +/- 0.10 at z=0.32 and 0.30 +/- 0.07 at z=0.57, the latter
constituting the highest redshift at which this quantity has been determined.
These measurements are consistent with the predictions of General Relativity,
for a perturbed Friedmann-Robertson-Walker metric in a Universe dominated by a
cosmological constant, which are E_G = 0.41 and 0.36 at these respective
redshifts. The combination of redshift-space distortion and gravitational
lensing data from current and future galaxy surveys will offer increasingly
stringent tests of fundamental cosmology.
