Appears in collection : 2024 - PC1 - WS - Curved spacetimes, field theory and beyond

We present results on reconstruction of linear and nonlinear wave operators from knowledge of their near field and far field effect on incoming waves. Connections with unique continuation and nonlinear Goursat problems will be made. Based on joint work with Ali Feizomohammadi, Lauri Oksanen, Hiroshi Isozaki, Matti Lassas, and Teemu Tyni.