December 10, 2026, 14:00 CET; Online (Zoom)
In autumn 2026, within a few weeks a series of papers showed that the perturbation equations of several black-hole spacetimes can be separated into ordinary differential equations, overcoming obstacles that had resisted for decades:
- P. Hintz, Perturbations of Kerr-Newman black holes: separation and mode stability, arXiv:2609.33661
- J. E. Santos, Separation of gravitational perturbations of singly spinning Myers-Perry black holes, arXiv:2610.18956
- O. J.C. Dias, J. E. Santos, Separation of variables for massive spin-2 fields on the Kerr black hole, arXiv:2610.40780
To celebrate “The Month of Separation”, we are organizing an informal online workshop. The authors will present their results, followed by talks on applications, including quasinormal modes and tidal Love numbers of Kerr-Newman black holes and massive spin-2 fields in Kerr.
Speakers: Kyriakos Destounis (IST Lisbon, Natl. Tech. U., Athens), Oscar Dias (Southampton U.), Peter Hintz (Penn State U.), Takuya Katagiri (Sapienza), Hayato Motohashi (Tokyo Metropolitan U.), Jorge Santos (Cambridge U.), Jun-Kun Zhao (Beijing, Inst. Theor. Phys.)
Program: (times refer to CET).
14:00: P. Hintz - Perturbations of Kerr-Newman black holes: separation and mode stability (30+10min)
14:40: J. Santos, Separation of gravitational perturbations of singly spinning Myers-Perry black holes (30+10min)
15:20: H. Motohashi - Charge-regular formulation and radiative amplitudes of Kerr–Newman perturbations (25+5 min)
15:50-16:00: break
16:00: JK Zhao, TBA (25+5 min)
16:30: O. Dias, Separation of variables for massive spin-2 fields on the Kerr black hole (30+10min)
17:10: T. Katagiri, Vanishing Love Numbers of Kerr-Newman Black Holes (25+5 min)
17:40: K. Destounis, Quasinormal modes of Kerr-Newman Black Holes (25+5 min)
18:10-19:00: Discussion
Zoom link: to be announced.
Organizer: Paolo Pani (Sapienza University of Rome)
Support: This event is supported by FIS (Italian Ministry of University and Research), Sapienza University of Rome, and INFN.