Acceleration techniques for regularized Newton methods applied to electromagnetic inverse medium scattering problems

Abstract: We study the construction and updating of spectral preconditioners for regularized Newton methods and their application to electromagnetic inverse medium scattering problems. Moreover, we show how a Lepski\u{i}-type stopping rule can be implemented efficiently for these methods. In numerical examples, the proposed method compares favorably with other iterative regularization method in terms of work-precision diagrams for exact data. For data perturbed by random noise, the Lepski\u{i}-type stopping rule performs considerably better than the commonly used discrepancy principle.