Download this article
 Download this article For screen
For printing
Recent Issues

Volume 18
Issue 5, 1065–1308
Issue 4, 805–1064
Issue 3, 549–803
Issue 2, 279–548
Issue 1, 1–278

Volume 17, 10 issues

Volume 16, 10 issues

Volume 15, 8 issues

Volume 14, 8 issues

Volume 13, 8 issues

Volume 12, 8 issues

Volume 11, 8 issues

Volume 10, 8 issues

Volume 9, 8 issues

Volume 8, 8 issues

Volume 7, 8 issues

Volume 6, 8 issues

Volume 5, 5 issues

Volume 4, 5 issues

Volume 3, 4 issues

Volume 2, 3 issues

Volume 1, 3 issues

The Journal
About the journal
Ethics and policies
Peer-review process
 
Submission guidelines
Submission form
Editorial board
Editors' interests
 
Subscriptions
 
ISSN 1948-206X (online)
ISSN 2157-5045 (print)
 
Author index
To appear
 
Other MSP journals
Stability and Lorentzian geometry for an inverse problem of a semilinear wave equation

Matti Lassas, Tony Liimatainen, Leyter Potenciano-Machado and Teemu Tyni

Vol. 18 (2025), No. 5, 1065–1118
Abstract

This paper concerns an inverse boundary value problem for a semilinear wave equation on a globally hyperbolic Lorentzian manifold. We prove a Hölder stability result for recovering an unknown potential q of the nonlinear wave equation gu + qum = 0, m 4, from the Dirichlet-to-Neumann map. Our proof is based on the recent higher-order linearization method and use of Gaussian beams. We also extend earlier uniqueness results by removing the assumptions of convex boundary and that pairs of light-like geodesics can intersect only once. For this, we construct special light-like geodesics and other general constructions in Lorentzian geometry. We expect these constructions to be applicable in studies of related problems as well.

Keywords
Lorentzian geometry, nonlinear wave equations, inverse problems
Mathematical Subject Classification
Primary: 35L71, 58J45
Secondary: 35L05
Milestones
Received: 30 November 2022
Revised: 17 January 2024
Accepted: 11 April 2024
Published: 10 May 2025
Authors
Matti Lassas
Department of Mathematics and Statistics
University of Helsinki
Helsinki
Finland
Tony Liimatainen
Department of Mathematics and Statistics
University of Helsinki
Helsinki
Finland
Department of Mathematics and Statistics
University of Jyväskylä
Jyväskylä
Finland
Leyter Potenciano-Machado
Department of Mathematics and Statistics
University of Jyväskylä
Jyväskylä
Finland
Teemu Tyni
Research Unit of Applied and Computational Mathematics
University of Oulu
Oulu
Finland
Department of Mathematics and Statistics
University of Helsinki
Helsinki
Finland

Open Access made possible by participating institutions via Subscribe to Open.