Comparison of diagonal variances for the gamma–shear cross-power spectra. Each subplot corresponds to one tomographic redshift bin (columns, from z1 to z6) and one Fermi–LAT energy bin (rows, from e1 to e10). The diagonal elements Var(C_ℓ^gκ) are shown in the five multipole bins used in the measurement. The jackknife estimates are shown in green, the NaMaster Gaussian covariance based on analytical power spectra in blue, and that based on measured power spectra in black.