Asma Salem Al-Luhaybi2022-05-192022-05-191106https://drepo.sdl.edu.sa/handle/20.500.14154/9831This thesis introduces and study new types of geodesics of flat RobertsonWalker space. Types of the retractions, deformation retracts and foldings of flat Robertson-Walker space are presented. The relations between new types of the geodesics, foldings and the deformation retracts of submanifolds of flat Robertson-Walker space are deduced. Also, the isometric and topological folding in each case and the relation between the deformation retracts after and before folding have been obtained. The conenThesis