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arXiv · 2509.17710

A posteriori existence for the Keller-Segel model via a finite volume - finite element scheme

Marc Hoffmann·Jan Giesselmann
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Abstract

We derive two forms of conditional a posteriori error estimates for a finite volume scheme approximating the parabolic-elliptic Keller-Segel system. The estimates control the error in the $L^\infty(0,T, L^2(\Omega))$- and $L^2(0,T;H^1(\Omega))$-norm and exhibit linear convergence in the mesh size, as observed in numerical experiments. Crucially, we show that, as long as the condition of the error estimate is satisfied, a weak solution exists. This means, as long as the numerical solution has good properties, we can rigorously infer existence of an exact solution.

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Marc Hoffmann, Jan Giesselmann. 2025-09-22. A posteriori existence for the Keller-Segel model via a finite volume - finite element scheme. https://arxiv.org/abs/2509.17710

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