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arXiv · 2601.21018

Identification of space-dependent coefficients in two competing terms of a nonlinear subdiffusion equation

Barbara Kaltenbacher·William Rundell
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Abstract

We consider a (sub)diffusion equation with a nonlinearity of the form $pf(u)-qu$, where $p$ and $q$ are space dependent functions. Prominent examples are the Fisher-KPP, the Frank-Kamenetskii-Zeldovich and the Allen-Cahn equations. We devise a fixed point scheme for reconstructing the spatially varying coefficients from interior observations a) at final time under two different excitations b) at two different time instances under a single excitation. Convergence of the scheme as well as local uniqueness of these coefficients is proven. Numerical experiments illustrate the performance of the reconstruction scheme.

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Barbara Kaltenbacher, William Rundell. 2026-01-28. Identification of space-dependent coefficients in two competing terms of a nonlinear subdiffusion equation. https://arxiv.org/abs/2601.21018

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