Mounir. REDJOUHSalim. Mesbahi2024-03-242024-03-242021http://dspace.univ-skikda.dz:4000/handle/123456789/521The work that constitutes this thesis is a contribution to the modeling and mathematical analysis of reaction diffusion systems. We are interested in the existence of continuous positive solutions of a class of nonlinear parabolic reaction diffusion systems with initial conditions; using techniques based on functional analysis and potential analysis. This work is then composed of three independent chapters, it is preceded by a general introduction that highlights the art of the subject and the problems addressed.enThesis