G5 Doctoral dissertation (article)
Inverse problems for the minimal surface equation and semilinear elliptic partial differential equations (2024)


Nurminen, J. (2024). Inverse problems for the minimal surface equation and semilinear elliptic partial differential equations [Doctoral dissertation]. University of Jyväskylä. JYU Dissertations, 780. https://urn.fi/URN:ISBN:978-952-86-0159-3


JYU authors or editors


Publication details

All authors or editorsNurminen, Janne

eISBN978-952-86-0159-3

Journal or seriesJYU Dissertations

eISSN2489-9003

Publication year2024

Number in series780

Number of pages in the book1 verkkoaineisto (17 sivua, 77 sivua useina numerointijaksoina, 10 numeroimatonta sivua)

PublisherUniversity of Jyväskylä

Place of PublicationJyväskylä

Publication countryFinland

Publication languageEnglish

Persistent website addresshttps://urn.fi/URN:ISBN:978-952-86-0159-3

Publication open accessOpenly available

Publication channel open accessOpen Access channel


Abstract

This thesis focuses on studying inverse problems for nonlinear elliptic partial differential
equations and in particular inverse problems for the minimal surface equation and semilinear
elliptic equations. It is shown that one can recover information about the coefficients of the
equation or some geometric information from boundary measurements of solutions. The main
tool used is linearization, both first order and higher order linearization.
The introduction describes inverse problems for partial differential equations in the context of
the Calder´on problem and gives a survey of the literature related to the linearization methods.
Main theorems of the included articles are presented and the methods to prove them are also
discussed.
The articles (A) and (C) focus on inverse problems for the minimal surface equation. In both
articles we look at the minimal surface equation in Euclidean space that is equipped with a
Riemannian metric. Then from boundary measurements we determine information about the
metric. In (A) the metric is conformally Euclidean and in (C) the metric will be in a class of
admissible metrics. The main method used in both articles is the higher order linearization
method.
The remaining articles (B) and (D) study inverse problems for semilinear elliptic equations.
In (B) the equation has a power type nonlinearity and the aim is to determine an unbounded
potential from boundary measurements. Also in (B) the method used is the higher order
linearization method. In (D) the focus is on recovering a general zeroth order nonlinearity from
boundary measurements. Here the first linearization is used and we improve previous results
for this method in the case of semilinear equations.


Keywordspartial differential equationsinverse problems

Free keywordslinearisaatio


Contributing organizations


Ministry reportingYes


Last updated on 2024-21-05 at 16:29