Matter power spectrum in the CDM runs at z = 0 for the DMO (black) and the FP runs separated into different components (coloured curves). The dotted lines show the prediction from linear theory, while the yellow line shows the result from Springel et al. (2018) for the larger TNG300-1 box. We used the two high-resolution boxes, 100/A (solid lines) and 50/A (dashed lines). All power spectra are computed with a grid of size 2048³, leading to Nyquist frequencies for the two cases of k = 85.8 h Mpc⁻¹ and k = 183 h Mpc⁻¹, respectively. Here and in the following figures, we used these values to limit the curves and plot the remaining points as a fainter line.