Non Local Mixed Systems with Neumann Boundary Conditions
Rinaldo M. Colombo, Elena Rossi, Abraham Sylla
TL;DR
The article develops an $L^1$ well-posedness and stability theory for a nonlinear, nonlocal mixed hyperbolic–parabolic system on a bounded domain with Neumann boundary conditions for the parabolic part. The hyperbolic and parabolic components are analyzed separately, yielding existence, uniqueness, positivity, and continuous dependence results, then glued together for the full coupled system via a fixed-point scheme that alternates solving each subproblem. A Neumann Green function representation provides a robust parabolic solution formula, and a careful $L^1$ framework ensures global-in-time solvability under broad, biologically motivated assumptions. These results extend existing $L^2$–based treatments by delivering a rigorous $L^1$ theory applicable to predator–prey and control applications where mass conservation and no-flux boundaries are essential. The combination of approximation arguments, Green function techniques, and contraction on short time intervals enables a global existence proof and quantitative stability estimates with respect to initial data and forcing terms.
Abstract
We prove well posedness and stability in $\mathbf{L}^1$ for a class of mixed hyperbolic-parabolic non linear and non local equations in a bounded domain with no flow along the boundary. While the treatment of boundary conditions for the hyperbolic equation is standard, the extension to $\mathbf{L}^1$ of classical results about parabolic equations with Neumann conditions is here achieved.
