Hyperboloidal slicing without geometry & a practical algorithm for QNM orthogonality

Lionel London (KCL, London)

Jan 15. 2026, 15:00 — 15:30

I'll present a novel gauge and tetrad fixing approach called parameterized field regularization (PFR), which is motivated by algebraic equivalence transformations. As a primary example, PFR is applied to Kerr quasi-normal modes (QNMs), resulting in a coordinate gauge and tetrad choice in which the mode functions are always finite on the black hole exterior. The resulting spacetime coordinates are functionally equivalent to the known “Cauchy fixing” hyperboloidal coordinates; however, our construction and tetrad choice differ from that used in the hyperboloidal framework. Lastly, I'll proof-of-concept results on a practical algorithm for QNM projection, given the output of a hyperboloidal numerical evolution. 

Further Information
Venue:
ESI Boltzmann Lecture Hall
Associated Event:
Hyperboloidal Foliations and their Application (Workshop)
Organizer(s):
Roland Donninger (U of Vienna)
David Hilditch (IST Lisboa)
Maciej Maliborski (TU Wien)
Rodrigo Panosso Macedo (NBI, Copenhagen)
Alex Vañó Viñuales (U de Les Illes Balears)
Anil Colpan Zenginoglu (U of Maryland)