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 σ₈. 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, σ₈(z = 0.57) = 0.55 ± 0.07 and Ω_m = 0.31 ± 0.08, in agreement with Planck cosmological results 2018. We also estimate the probe of gravity E_G = 0.43 ± 0.10, in agreement with ΛCDM-GR predictions of E_G = 0.40. This analysis reveals that RSD efficiently decreases the GGL uncertainty on Ω_m by a factor of 4 and by 30% on σ₈. We make our mock catalogues available on the Skies and Universe database.

The catalogues are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/627/A137 and at http://www.skiesanduniverses.org