Special Session 48: Recent Advances in Nonlinear PDEs and Inverse Problems

Inverse Problems for Anisotropic Conductivities in Semilinear Models
Elisa Francini
Universit\`a di Firenze
Italy
Co-Author(s):    Elena Beretta, Dario Pierotti, Eva Sincich
Abstract:
In this talk, we discuss an inverse boundary value problem arising in a semilinear elliptic model motivated by cardiac electrophysiology. The model describes the stationary behavior of the transmembrane potential under pacing and involves an anisotropic conductivity tensor together with a nonlinear ionic response. We address the problem of recovering a piecewise constant anisotropic conductivity from boundary measurements encoded by the Neumann-to-Dirichlet map. Assuming that the nonlinear coefficient and the geometry of the inclusion are known, we present a uniqueness result showing that the conductivity is uniquely determined by the boundary data. The analysis is based on a first-order linearization of the nonlinear map around a nontrivial background state, leading to a linear elliptic problem with a strictly positive zeroth-order term. This reduction allows us to combine boundary determination techniques for anisotropic conductivities with unique continuation arguments to achieve identifiability.