ALI CHIKOUCHE, ImaneDECHOUCHA, Noureddine: Supervisor2024-07-022024-07-022024-06https://dspace.univ-msila.dz/handle/123456789/43046In this work, we study the existence of renormalized and entropy (weak) solutions of nonlinear parabolic system defined by ∂u1 ∂t − div(A1(u1, ∇u1) − div(k1u1 + f(u)) = −σ(u1, u2, u3) − µ1u1 + f in QT The same equations with u2 and u3. The method of solving our problem consist of obtaining local estimates for suitable approximate problems and then passing to the limit. This problem is taken from the article [18], that is published in 2013. Which will be used in detailed proofsenEntropy solotionsnonlinear parabolic systemsEntropy solotions of nonlinear parabolic systemsThesis