Testing gravity with galaxy-galaxy lensing and redshift-space distortions using CFHT-Stripe 82, CFHTLenS, and BOSS CMASS datasets

The combination of galaxy-galaxy lensing (GGL) and redshift space distortion of galaxy clustering (RSD) is a privileged technique to test general relativity predictions and break degeneracies between the growth rate of structure parameter f and the amplitude of the linear power spectrum σ<SUB>8</SUB>. We performed a joint GGL and RSD analysis on 250 sq. deg using shape catalogues from CFHTLenS and CFHT-Stripe 82 and spectroscopic redshifts from the BOSS CMASS sample. We adjusted a model that includes non-linear biasing, RSD, and Alcock-Paczynski effects. We used an N-body simulation supplemented by an abundance matching prescription for CMASS galaxies to build a set of overlapping lensing and clustering mocks. Together with additional spectroscopic data, this helps us to quantify and correct several systematic errors, such as photometric redshifts. We find f(z = 0.57) = 0.95 ± 0.23, σ<SUB>8</SUB>(z = 0.57) = 0.55 ± 0.07 and Ω<SUB>m</SUB> = 0.31 ± 0.08, in agreement with Planck cosmological results 2018. We also estimate the probe of gravity E<SUB>G</SUB> = 0.43 ± 0.10, in agreement with ΛCDM-GR predictions of E<SUB>G</SUB> = 0.40. This analysis reveals that RSD efficiently decreases the GGL uncertainty on Ω<SUB>m</SUB> by a factor of 4 and by 30% on σ<SUB>8</SUB>. We make our mock catalogues available on the Skies and Universe database. The catalogues are available at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr/'>http://cdsarc.u-strasbg.fr</A> (ftp://130.79.128.5) or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/627/A137'>http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/627/A137</A> and at <A href='http://www.skiesanduniverses.org'>http://www.skiesanduniverses.org</A>