Abstract
In this work we tackle the reconstruction of discontinuous coefficients in a semilinear elliptic equation from the knowledge of the solution on the boundary of the planar bounded domain. The problem is motivated by an application in cardiac electrophysiology. We formulate a constraint minimization problem involving a quadratic mismatch functional enhanced with a regularization term which penalizes the perimeter of the inclusion to be identified. We introduce a phase-field relaxation of the problem, employing a Ginzburg-Landau-type energy and assessing the Γ-convergence of the relaxed functional to the original one. After computing the optimality conditions of the phase-field optimization problem and introducing a discrete finite element formulation, we propose an iterative algorithm and prove convergence properties. Several numerical results are reported, assessing the effectiveness and the robustness of the algorithm in identifying arbitrarily-shaped inclusions. Finally, we compare our approach to a shape derivative based technique, both from a theoretical point of view (computing the sharp interface limit of the optimality conditions) and from a numerical one.
Original language | English (US) |
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Pages (from-to) | 1975-2002 |
Number of pages | 28 |
Journal | Communications in Mathematical Sciences |
Volume | 16 |
Issue number | 7 |
DOIs | |
State | Published - 2018 |
Keywords
- Inverse problem
- Phase-field relaxation
- Semilinear elliptic equation
ASJC Scopus subject areas
- General Mathematics
- Applied Mathematics