Quasinormal modes

Quasinormal modes-shadow correspondence for rotating regular black holes

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.

Davide Pedrotti's MSc defense

Congratulations to Davide Pedrotti, who today successfully defended his MSc thesis, by the title of “Studies on Quasi-Normal Modes and Shadows of Black Holes” (with the opponent being Prof. Albino Perego)! Davide’s defense was outstanding (one of the committee members, a condensed matter physicist, said: “This is the first talk on black holes I’ve understood in years”), and in fact he received top grades and honours, i.e. 110 e Lode. In his thesis, supervised by myself and Prof. Kostas Kokkotas at the University of Tübingen, Davide studied quasi-normal modes and shadows of a number of well-motivated BH metrics beyond GR, and in particular investigated the non-trivial correspondence between the two for metrics describing rotating regular BHs: part of his thesis will be written up in a paper in the coming months, so stay tuned! During the same day, I also served as opponent for an MSc student of Prof. Bill Weber. Davide will now be enjoying a few days of deserved break before starting hiw new adventure as a PhD student in Trento in November.

New (first) group member!

Today Davide Pedrotti joins my group as a new Master’s student. Davide is enrolled in the Trento-Tübingen Double Degree, and will be jointly supervised by me in Trento, and by Prof. Kostas Kokkotas in Tübingen. While the finer details remain to be defined, Davide’s thesis will be on the topic of quasi-normal modes of black holes beyond GR, their use in testing gravity, and potentially their connection to black hole shadows. Welcome Davide, and looking forward to our work together!