Stability of determining the potential from partial boundary data in a Schrödinger equation in the high frequency limit
Mourad Choulli
TL;DR
This work proves stability estimates for recovering a Schrödinger potential $q$ from partial boundary data in the high-frequency regime on a bounded domain in 3D. The authors develop a quantitative framework combining quantitative unique continuation, Runge approximation, and complex geometric optics (CGO) solutions to relate interior information $\hat{q}(\eta)$ to boundary measurements encoded in partial Dirichlet-to-Neumann maps $\Lambda_{q,\lambda}^0$ (and $\Lambda_{q,\lambda}^1$). The main result is a double-logarithmic stability bound of the form $\|q_1-q_2\|_{H^{-1}(M)} \le C \mathbf{m}_\lambda \big|\ln\ln \|\Lambda_{q_1,\lambda}^0-\Lambda_{q_2,\lambda}^0\|\big|^{-2/(n+2)}$ for small data discrepancies, with explicit frequency-dependent constants and a clear dependence on the distance to the spectrum via $\mathbf{e}_\lambda$. The analysis extends to the interior impedance problem, employing corresponding boundary maps $\mathscr{N}_{q,\mu}^0$, $\mathscr{N}_{q,\mu}^1$ and showing the robustness of the approach under impedance boundaries. Overall, the paper provides a rigorous, frequency-aware, quantitative stability theory for partial-data inverse Schrödinger problems in three dimensions, including a pathway to generalize the results to related boundary conditions.
Abstract
We establish stability inequalities for the problem of determining the potential, appearing in a Schödinger equation, from partial boundary data in the high frequency limit. These stability inequalities hold under the assumption that the potential is known near the boundary of the domain under consideration.
