Numerical black hole binary mergers beyond general relativity

At some scale, Einstein’s classical theory of general relativity (GR) must break and be reconciled with quantum mechanics in a beyond-GR theory. Binary black hole (BBH) mergers probe the non-linear, strong-field regime of gravity, and thus gravitational wave (GW) signals from these systems could contain signatures of a beyond-GR theory. However, numerical GW signal predictions have only been produced in GR, thus allowing for null and parametrized tests of GR, but no model-dependent test of gravity. I will present our recent work in producing numerical BBH waveforms in beyond-GR theories, starting with dynamical Chern-Simons gravity (DCS), an effective field theory with origins in string theory, loop quantum gravity, and inflation. In particular, I will present black hole gravitational waveforms from binary black hole collisions in DCS, analyze the quasi-normal mode spectra of the ringdown, and place detectability estimates on parameters governing this beyond-GR theory. Additionally, I will briefly discuss our recent work on numerical black hole shadows in DCS.