Inverse Boundary Value Problems for Wave Equations with Quadratic Nonlinearities

Gunther Uhlmann, Yang Zhang

We study inverse problems for the nonlinear wave equation ${\square }_{g}u+w(x,u,{\nabla }_{g}u)=0$ in a Lorentzian manifold $(M,g)$ with boundary, where ${\nabla }_{g}u$ denotes the grad…