Existence of a global weak solution for a reaction-diffusion problem with membrane conditions

Giorgia Ciavolella (1, 2) , Benoît Perthame (1, 2)

1 LJLL (UMR_7598) - Laboratoire Jacques-Louis Lions
2 MAMBA - Modelling and Analysis for Medical and Biological Applications

Several problems, issued from physics, biology or the medical science, lead to parabolic equations set in two sub-domains separated by a membrane with selective permeability to specific molecules. The corresponding boundary conditions, describing the flow through the membrane, are compatible with mass conservation and energy dissipation, and are called the Kedem-Katchalsky conditions. Additionally, in these models, written as reaction-diffusion systems, the reaction terms have a quadratic behaviour. M. Pierre and his collaborators have developed a complete $L^1$ theory for reaction-diffusion systems with different diffusions. Here, we adapt this theory to the membrane boundary conditions and prove the existence of weak solutions when the initial data has only $L^1$ regularity using the truncation method for the nonlinearities. In particular, we establish several estimates as the $W^{1,1}$ regularity of the solutions. Also, a crucial step is to adapt the fundamental $L^2$ (space, time) integrability lemma to our situation.

Mots clés: Mathematical biology; Kedem-Katchalsky conditions; Membrane boundary conditions; Reaction-diffusion equations

Domaines: Equations aux dérivées partielles [math.AP]; Mathématiques [math]

Giorgia Ciavolella, Benoît Perthame. Existence of a global weak solution for a reaction-diffusion problem with membrane conditions. Journal of Evolution Equations, 2020, ⟨10.1007/s00028-020-00633-7⟩. ⟨hal-02905180v3⟩