Fatima, SalmiEncadreur: Bachir, Gagui2025-07-072025-07-072025-06-14https://repository.univ-msila.dz/handle/123456789/46714This dissertation deals with the existence of solutions to fractional order differential equations of Riemann-Liouville type in Orlicz spaces, based on fixed point theory and Kuratowsli’s measure of noncomactness.enFractional differential equationsRiemann–LiouvilleOrlicz spacesfixed point theoryKuratowski’s measure of noncompactnessFractional differential equations in Orlicz spacesThesis