Fast reconstruction of harmonic functions from Cauchy data using integral equation techniques

Johan Helsing, B. Tomas Johansson

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We consider the problem of stable determination of a harmonic function from knowledge of the solution and its normal derivative on a part of the boundary of the (bounded) solution domain. The alternating method is a procedure to generate an approximation to the harmonic function from such Cauchy data and we investigate a numerical implementation of this procedure based on Fredholm integral equations and Nyström discretization schemes, which makes it possible to perform a large number of iterations (millions) with minor computational cost (seconds) and high accuracy. Moreover, the original problem is rewritten as a fixed point equation on the boundary, and various other direct regularization techniques are discussed to solve that equation. We also discuss how knowledge of the smoothness of the data can be used to further improve the accuracy. Numerical examples are presented showing that accurate approximations of both the solution and its normal derivative can be obtained with much less computational time than in previous works.
    Original languageEnglish
    Pages (from-to)381-399
    Number of pages19
    JournalInverse Problems in Science and Engineering
    Volume18
    Issue number3
    DOIs
    Publication statusPublished - 2010

    Keywords

    • alternating method
    • second kind boundary integral equation
    • Nyström method
    • Laplace equation
    • Cauchy problem

    Fingerprint

    Dive into the research topics of 'Fast reconstruction of harmonic functions from Cauchy data using integral equation techniques'. Together they form a unique fingerprint.

    Cite this