Massless fermions in spatially flat FLRW space-times

Abstract The propagation of the packets left-handed plane wave solutions massless Dirac equation is studied in spatially flat Friedmann–Lemaître–Robertson–Walker (FLRW) space-times. Assuming that observations are performed physical frames with Painlevé–Gullstrand coordinates, current and energy–momentum tensor derived, emphasising their severe decay moderate dispersion during propagation. As move along null geodesics, interesting effects produced by apparent or event horizons.