Evolution of the UV luminosity function at M_UV​ = ​ − 17 (left) and −20 (right). Similar to Fig. 5, the colored bands represent dust-corrected FFB predictions for ϵ_max​ = ​0.2 (orange) or 1 (blue) and the gray line shows the fiducial UM model (B19). The UVLFs uncorrected for dust are shown by dashed lines. The FFB predictions at M_UV​ = ​ − 20 are higher than the UM model starting at z​ ∼ ​7 and more so at higher redshifts. The open gray data points in the right panel are JWST measurements (Adams et al. 2024; Finkelstein et al. 2023a; McLeod et al. 2024). The tentative comparison indicates a fit with ϵ_max​ ∼ ​0.2 at z​ = ​8 − 12 and possibly higher efficiencies at higher redshifts.