Reconstructions for the primordial power spectra and their corresponding CMB pseudo spectra. In blue we show the 2000 reconstructed spectra with n_s = 0.972 and α_s = 0 and in cyan the reconstruction for n_s = 0.972 and α_s = −0.017. In both cases the mean of the reconstructions is shown in orange and the fiducial input spectrum is shown in red. As can be seen, for k> 0.015Mpc^-1 PRISM can reconstruct the primordial power spectra with such accuracy that the two are easily distinguishable, despite their very similar forms in C_ℓ space. The shaded regions in panel b) correspond to the 1σ sample (cosmic) variance, which demonstrates the similarity of the two types of CMB spectra. The quality of the reconstruction can also be seen in the reconstructed angular power spectra which are extremely close to the theory and well within the 1σ sample variance intervals.