I’m truly thrilled to see my latest preprint with my PhD student Davide Pedrotti, which also happens to be Davide’s first paper, out on arXiv! This work is the one I was anticipating in an earlier news item, and is based on part of Davide’s MSc thesis - so, needless to say, kudos to Davide who did all the hard work! There is a well-known correspondence between black hole quasinormal modes (QNMs) in the eikonal limit (ℓ>>1), and the size of BH shadows: this correspondence has been extensively studied for spherically symmetric space-times, but the extension to rotating space-times is non-trivial, and has only been worked out either only for equatorial QNMs (m=±ℓ), or for general QNMs but limited to the Kerr metric. What we did with Davide was to extend this correspondence to more general rotating space-times, then testing it explicitly on the rotating regular Bardeen and Hayward BHs, while also discussing the conditions under which the correspondence holds within general rotating space-times (basically the Hamilton-Jacobi and Klein-Gordon equations have to be separable). You can read our results in the preprint we just posted on arXiv (with what I think is a pretty cool title): 2404.07589.
