Upper panel: power spectra for the DM-only simulation, obtained by using n³ grids with effective n from 1024 to 32 768, are shown at z = 0 (solid curves) and z = 4.62 (dashed curves). The latter is the highest redshift at which non-linear spectral features are (barely) visible above the numerical noise. In contrast, at z = 0, numerical noise affects only the spectrum at the highest resolution. Lower panel: the ratios of P_f(k) (f = 0,..., 4) to P₅(k) are plotted. Values of this ratio at the two considered redshifts are almost indistinguishable and this plot explicitly shows that they do not depend on the extension of numerical noise and are self-similar when the resolution limit is shifted.