Counterexamples to the Lorentzian Calder\'on problem
Analysis of PDEs
2026-04-23 v1 Differential Geometry
Abstract
We show that two non-isometric, smooth, globally hyperbolic Lorentzian metrics can have the same hyperbolic Dirichlet-to-Neumann map on an infinite cylinder with timelike boundary.
Cite
@article{arxiv.2604.20320,
title = {Counterexamples to the Lorentzian Calder\'on problem},
author = {Lauri Oksanen and Miika Sarkkinen},
journal= {arXiv preprint arXiv:2604.20320},
year = {2026}
}