Constraints on S8 from a full-scale and full-shape analysis of redshift-space clustering and galaxy-galaxy lensing in BOSS

We present a no v el simulation-based cosmological analysis of g alaxy-g alaxy lensing and galaxy redshift-space clustering. Compared to analysis methods based on perturbation theory, our simulation-based approach allows us to probe a much wider range of scales, 0 . 4 h (-1) Mpc to 63 h (-1) Mpc , including highly non-linear scales, and marginalizes o v er astrophysical effects such as assembly bias. We apply this framework to data from the Baryon Oscillation Spectroscopic Survey LOWZ sample cross-correlated with state-of-the-art gravitational lensing catalogues from the Kilo Degree Survey and the Dark Energy Survey . We show that gravitational lensing and redshift-space clustering when analysed o v er a large range of scales place tight constraints on the growth-of-structure parameter S-8 = sigma 8 root omega(m) / 0 . 3 . Overall, we infer S (8) = 0.792 +/- 0.022 when analysing the combination of g alaxy-g alaxy lensing and projected g alaxy clustering and S 8 = 0.771 +/- 0.027 for g alaxy redshift-space clustering. These findings highlight the potential constraining power of full-scale studies o v er studies analysing only large scales and also showcase the benefits of analysing multiple large-scale structure surv e ys jointly. Our inferred values for S 8 fall below the value inferred from the CMB, S 8 = 0.834 +/- 0.016. While this difference is not statistically significant by itself, our results mirror other findings in the literature whereby low-redshift large-scale structure probes infer lo wer v alues for S 8 than the CMB, the so-called S8-tension.