Abstract

Einstein’s theory of General Relativity has passed all tests to date in the quasi-stationary weak-field, where the gravitational force is weak and velocities are small. In the near future, gravitational wave detections will allow us to test Einstein’s theory to new, exciting levels in the strong-field regime, such as in the neighborhood of black holes and when compact objects collide. In particular, the gravitational waves emitted as a small object compact spirals into a supermassive black hole, an extreme mass-ratio inspiral, serve as a tracer of the latter’s background geometry. Such a ``geometry’’ map would, for the first time, allow us to test the Kerr hypothesis and the black hole uniqueness theorems of General Relativity. In this talk, I will review recent work on black holes outside of General Relativity and extreme-mass ratio inspirals, aimed at understanding how these new tests of Einstein’s theory can be carried out in the coming era of precision gravitational wave astrophysics.