New paper from a new student! Here is Matteo Boschini’s first piece of work, where we look at predictions for the final mass and spins of black-hole remnants. That is, after two black hole merge, what’s the mass and spin of the guy they left behind? These predictions are typically done by fitting (in various ways) outputs from numerical-relativity simulations but those, unfortunately, can only handle black holes of similar masses. On the other hand, black holes with masses that are very different from each other can be handled analytically. Here we show how to put the two together with a single machine-learning fit.

Matteo Boschini, Davide Gerosa, Vijay Varma, Cristobal Armaza, Michael Boyle, Marceline S. Bonilla, Andrea Ceja, Yitian Chen, Nils Deppe, Matthew Giesler, Lawrence E. Kidder, Guillermo Lara, Oliver Long, Sizheng Ma, Keefe Mitman, Peter James Nee, Harald P. Pfeiffer, Antoni Ramos-Buades, Mark A. Scheel, Nils L. Vu, and Jooheon Yoo.
Physical Review D 108 (2023) 084015.
arXiv:2307.03435 [gr-qc].