The sampling variance cancels when computing ratio between simulated power spectra, which eases the comparison with theoretical predictions. This figure shows a comparison between these ratios, when computed from the cosmo-SLICS (denoted with subscript “sim”) or from HALOFIT (subscript “th”). More precisely, we compute P_model(k)/P_FID(k) for both cases and for all 25 cosmological models, and examine the ratio between the two estimates at z = 120 (blue), z ∼ 0.6 (red) and z ∼ 0.0 (black).