Helvi Witek, University of Illinois, Urbana-Champaign — June 27, 2022

The observation of black holes — from the shadow of supermassive black holes like "our own" Sag A* to the gravitational waves emitted during black holes' coalescence — has opened a rich discovery space for astrophysics, fundamental physics, and cosmology. In particular, they enable qualitatively new tests of gravity in its most extreme, nonlinear regime. To link gravitational wave observations to extensions of general relativity (GR), and to infer parameters of the underlying theory of gravity, we need accurate waveform models in and beyond GR. In this talk, I will give an overview of recent advances in modeling compact binaries in modified theories of gravity with particular focus on numerical relativity beyond GR and I will highlight new dynamical phenomena that are absent in GR.