[Journal Club] Testing black hole eikonal correspondence

Adopting geometric-optics approximations in black hole spacetimes enables the construction of a mapping between black hole images and eikonal black hole quasinormal modes (QNMs). The real part and imaginary part of the QNM frequencies correspond to the ring size and the detailed ring structure of the image, respectively. In this talk, I will present my recent work on the possibility of testing this mapping using real black hole observations, without worrying too much about the uncertainties inherent in the astrophysical emission process near the black hole. The prospect of using this method to test gravitational theories will be discussed.