Increasing stability in the linearized inverse Schrödinger potential problem with power type nonlinearities* *S Lu is supported by NSFC (No. 11925104), Science and Technology Commission of Shanghai Municipality (19XD1420500, 21JC1400500). M Salo is supported by the Academy of Finland (Finnish Centre of Excellence in Inverse Modelling and Imaging, Grant 284715) and by the European Research Council under Horizon 2020 (ERC

Abstract

We consider increasing stability in the inverse Schrödinger potential problem with power type nonlinearities at a large wavenumber. Two linearization approaches, with respect to small boundary data and small potential function, are proposed and their performance on the inverse Schrödinger potential problem is investigated. It can be observed that higher order linearization for small boundary data can provide an increasing stability for an arbitrary power type nonlinearity term if the wavenumber is chosen large. Meanwhile, linearization with respect to the potential function leads to increasing stability for a quadratic nonlinearity term, which highlights the advantage of nonlinearity in solving the inverse Schrödinger potential problem. Noticing that both linearization approaches can be numerically approximated, we provide several reconstruction algorithms for the quadratic and general power type nonlinearity terms, where one of these algorithms is designed based on boundary measurements of multiple wavenumbers. Several numerical examples shed light on the efficiency of our proposed algorithms.