Planck measurements of the lensing power spectrum compared to the prediction for the best-fitting Planck+WP+highL ΛCDM model parameters. In the top panel, the data points are the measured bandpowers and ± 1σ error ranges from the diagonal of the covariance matrix. The measured bandpowers are compared to the in the best-fit model (black line). The grey region shows the 1σ range in due to ΛCDM parameter uncertainties. The lower panel shows the differences between the bandpower amplitudes Â_i and the predictions for their expectation values in the best-fit model, .