Abstract:
Our current understanding of black holes assumes that they are described by the Kerr solution to Einstein's equations. On April 10, 2019, the Event Horizon Telescope (EHT), released the first image of a black hole resolved to event horizon scales and the first measurement of the size of a black-hole shadow. In October of 2020 we published a new test of general relativity at the 2PN order based on this measurement. I will discuss how we can use the Event Horizon Telescope to test the Kerr nature of black holes, both with this first image and in the future.