Amplitude (top panel) and correlation length (bottom panel) as a function of redshift for different models and simulations. The continuous light blue (blue) lines are the results of fitting the observations with ℳ2 (ℳ3), a Gaussian model with constant (redshift-dependent) width and amplitude. The shaded regions represent the 1σ error on the A (L) parameters. The shaded blue region instead indicates the 16th and 84th percentiles of the A₀-A₁ (L₀-L₁) joint-posterior distribution, except for redshifts of z < 5.1, where only the 1σ upper limit of L is shown. The dashed brown, dash-dotted red, and dotted orange lines are the results of fitting the simulations (const λ, evolv λ, SCRIPT) with ℳ3.