Power spectrum of the z_reion(r) field obtained with the model ζ30 on the left and ζ55 on the right. k is the spatial frequency with dimension [cMpc⁻¹h]. The black line stands for the ground truth and the dotted coloured lines depict predictions with different training redshifts. The shaded areas depict the dispersion around the median (1st and 99th percentiles) for both prediction and ground truth.