Mosco convergence for H(curl) spaces, higher integrability for Maxwell's equations, and stability in direct and inverse EM scattering problems

TL;DR

This paper establishes sharp stability results for electromagnetic scattering problems, demonstrating how solutions depend continuously on scatterer and medium variations, and introduces new analytical tools for Maxwell's equations in complex domains.

Contribution

It proves Mosco convergence for H(curl) spaces and higher integrability of Maxwell solutions, enabling improved stability analysis for inverse scattering problems.

Findings

Sharp stability bounds for direct scattering problems.

Logarithmic stability estimates for inverse scatterer identification.

Development of new analytical tools for Maxwell equations in nonsmooth domains.

Abstract

This paper is concerned with the scattering problem for time-harmonic electromagnetic waves, due to the presence of scatterers and of inhomogeneities in the medium. We prove a sharp stability result for the solutions to the direct electromagnetic scattering problem, with respect to variations of the scatterer and of the inhomogeneity, under minimal regularity assumptions for both of them. The stability result leads to uniform bounds on solutions to the scattering problems for an extremely general class of admissible scatterers and inhomogeneities. The uniform bounds are a key step to tackle the challenging stability issue for the corresponding inverse electromagnetic scattering problem. In this paper we establish two optimal stability results of logarithmic type for the determination of polyhedral scatterers by a minimal number of electromagnetic scattering measurements. In order to prove the stability result for the direct electromagnetic scattering problem, we study two fundamental issues in the theory of Maxwell equations: Mosco convergence for H(curl) spaces and higher integrability properties of solutions to Maxwell equations in nonsmooth domains.