Sensitivity of the clustering ratio to the cosmological model, through left: isocontours of the function displaying the relative variation in the measured galaxy clustering ratio (with respect to the true cosmological model of the simulated data), which are induced by choosing a wrong cosmology in the redshift-distance conversion (i.e. a wrong guess of the cosmological parameters [Ω_m,Ω_X]). The redshift-space galaxy clustering ratio (left-hand side of Eq. (8)) is measured on scales (R,r) = (5,15)   h^-1 Mpc from the stacking of the 31 L_h halo catalogues (which were built in a cosmology with Ω_m = 0.27,Ω_Λ = 0.73). The isocontours measure the strength of the Alcock-Paczynski geometric distortions, the deformation of the cell within which galaxies are counted. Right: the corresponding variation of the predicted mass clustering ratio (right-hand side of Eq. (8)) with varying cosmology. This panel evidences the sensitivity of η to Ω_m through the shape of the transfer function.