Lyα LF predicted from our simulations (red with shaded area showing the 68% PI), compared to the three models of Nilsson et al. (2007, described in Sect. 1). Also shown, with the red dashed line, is the Lyα LF predicted from our simulations if we did not take into account RT effects. Additionally, the upper limit LF of Matthee et al. (2014) is shown in green. The grey region marks observational upper limits from Willis & Courbin (2005) and Cuby et al. (2007).