In this paper, we classify quasi-conformally flat generalized Sasakian-space forms under the assumption that characteristic vector field is Killing. Also Weyl-symmetric forms.

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 mo...