English

Inverse problem for the wave equation with a white noise source

Analysis of PDEs 2015-06-17 v2 Probability

Abstract

We consider a smooth Riemannian metric tensor gg on Rn\R^n and study the stochastic wave equation for the Laplace-Beltrami operator \pt2uΔgu=F\p_t^2 u - \Delta_g u = F. Here, F=F(t,x,ω)F=F(t,x,\omega) is a random source that has white noise distribution supported on the boundary of some smooth compact domain MRnM \subset \R^n. We study the following formally posed inverse problem with only one measurement. Suppose that gg is known only outside of a compact subset of MintM^{int} and that a solution u(t,x,ω0)u(t,x,\omega_0) is produced by a single realization of the source F(t,x,ω0)F(t,x,\omega_0). We ask what information regarding gg can be recovered by measuring u(t,x,ω0)u(t,x,\omega_0) on R+×\pM\R_+ \times \p M? We prove that such measurement together with the realization of the source determine the scattering relation of the Riemannian manifold (M,g)(M, g) with probability one. That is, for all geodesics passing through MM, the travel times together with the entering and exit points and directions are determined. In particular, if (M,g)(M,g) is a simple Riemannian manifold and gg is conformally Euclidian in MM, the measurement determines the metric gg in MM.

Keywords

Cite

@article{arxiv.1308.4879,
  title  = {Inverse problem for the wave equation with a white noise source},
  author = {Tapio Helin and Matti Lassas and Lauri Oksanen},
  journal= {arXiv preprint arXiv:1308.4879},
  year   = {2015}
}

Comments

25 pages

R2 v1 2026-06-22T01:13:26.976Z