Imane, BenyahiaSupervisor: Douadi, Drihem2025-07-032025-07-032025-06-15https://repository.univ-msila.dz/handle/123456789/46627In this thesis, we present some of the properties of modulation spaces, which are used in mathematical analysis, especially differential equations. To study these spaces, ,we give some key technical results needed in the proof of the main results. We present a summary of Lebesgue spaces and some inequalities, such as Nikolskiy-Triebel inequalities. In this thesis, we give some equivalent norms and duality in these spaces.enoduModulation spacesshort-term Fourier transformLebesgue spaceswindow functiondualityfunctional spacesThesis