Hyperboloidal Foliations and their Application

The workshop brings together researchers across mathematical relativity, geometric analysis, and gravitational wave physics to explore the theory and applications of hyperboloidal foliations. Spacelike surfaces that asymptotically approach null infinity offer a geometric framework for analyzing wave propagation, with implications for both analytical and numerical treatments of the Einstein field equations.

As a follow-up to our previous meeting in 2023, Infinity on a Gridshell, the workshop will highlight recent advances in black hole perturbation theory, gravitational self-force, and the nonlinear numerical evolution of asymptotically flat spacetimes. Particular attention will be given to the role of hyperboloidal methods in modeling gravitational radiation across the inspiral, merger, and ringdown phases of compact binary coalescence. We will also investigate new frontiers where hyperboloidal foliations may be applicable, such as electromagnetic scattering theory and quantum field theory.

Jan. 12, 2026
09:00 — 09:15
Registration
09:15 — 09:30
Welcome
10:00 — 10:30
Coffee Break
10:30 — 11:00
11:30 — 12:00
12:00 — 14:00
Lunch
14:00 — 14:30
Joerg Frauendiener (U of Otago)
The geometry of null-infinity
14:30 — 15:00
15:30 — 16:00
Coffee Break
16:00 — 16:30
Public talk: The Hyperboloidal Research Network David Hilditch (IST Lisboa)
Hyperboloidal Foliations and their Application
Jan. 13, 2026
09:30 — 10:00
10:30 — 11:00
Coffee Break
12:00 — 14:00
Lunch Break
14:00 — 14:30
Marina De Amicis (Perimeter Institute, Waterloo)
Dynamical quasinormal mode excitation
14:30 — 15:00
15:00 — 15:30
15:30 — 16:00
Coffee Break
16:00 — 16:30
Discussion: BHPT and GW modeling
Jan. 14, 2026
10:30 — 11:00
Group Photo & Coffee Break
11:00 — 11:30
Piotr T. Chruściel (U of Vienna)
On hyperbolic and holographic mass
11:30 — 12:00
Károly Csukás (WIGNER RCP, Budapest)
Controlling asymptotic charges of hyperboloidal initial data
12:00 — 14:00
Lunch Break
15:30 — 16:00
Pre-dinner Coffee Break
16:00 — 16:30
Discussion: Geometry & PDE Analysis
18:30 — 22:00
Workshop Dinner
Jan. 15, 2026
09:30 — 10:00
10:00 — 10:30
Christiana Pantelidou (UCD)
Non-modal effects: Transient Superradiance
10:30 — 11:00
Coffee Break
11:00 — 11:30
11:30 — 12:00
Lucas T. de Paula (UFABC, Santo André)
Pseudospectrum of rotating analog black holes
12:00 — 14:00
Lunch Break
14:00 — 14:30
Jérémy Besson (U de Bourgogne, Dijon)
Keldysh analysis of non-modal transient growth
15:30 — 16:00
Coffee Break
16:00 — 16:30
Discussion: BHPT Foundation
Jan. 16, 2026
10:00 — 10:30
10:30 — 11:00
Coffee Break
11:00 — 11:30
12:00 — 14:00
Lunch Break
14:00 — 14:30
Discussion: NR
14:40 — 15:00
Wrap Up
15:00 — 15:30
Free Discussion
15:30 — 16:00
Farewell Coffee Break

Organizers

Name Affiliation
Roland Donninger University of Vienna
David Hilditch Instituto Superior Técnico Lisboa
Maciej Maliborski Vienna University of Technology
Rodrigo Panosso Macedo Niels Bohr Institute
Alex Vañó Viñuales Universitat de les Illes Balears
Anil Colpan Zenginoglu University of Maryland

Attendees

Name Affiliation
Robert Beig University of Vienna
Jérémy Besson Université de Bourgogne
Piotr Bizoń Jagiellonian University
Andras Bonk University of Vienna
Patrick Bourg Radboud University
Valentin Boyanov Instituto Superior Técnico Lisboa
Piotr T. Chruściel University of Vienna
Wan Cong University of Vienna
Brad Cownden Universidade de Santiago de Compostela
Pedro H. Croti Siqueira Federal University of ABC
Károly Csukás WIGNER RCP
Marina De Amicis Perimeter Institute
Filip Ficek University of Vienna
Joerg Frauendiener University of Otago
Shalabh Gautam Beijing Institute of Mathematical Sciences and Applications (BIMSA)
Alexander Grant University of Southampton
Jose-Luis Jaramillo Université de Bourgogne
Colin Kühner University of Tübingen
Benjamin Leather University of Southampton
Lionel London King's College London
Oliver Long Max Planck Institute for Gravitational Physics
Jordan Marajh Queen Mary University of London
Marica Minucci Niels Bohr Institute
Clemens Oettl Universität Wien
Matthias Ostermann Bielefeld University
Janos Östör Radboud University
Christiana Pantelidou University College Dublin
Christian Peterson Borquez Instituto Superior Técnico Lisboa
István Rácz WIGNER RCP
Ariadna Ribes Metidier Niels Bohr Institute
Anna Sancassani University of Tübingen
Saradha Senthil Velu University of Tübingen
Lucas T. de Paula Federal University of ABC
Juan A. Valiente Kroon Queen Mary University of London
Tien Van Truong Center for Theoretical Physics, Polish Academy of Sciences
Aditya Vaswani University of Southampton
Corentin Vitel Université de Bourgogne
Salvatore Vultaggio University of Otago
Raphaela Wutte University of Southampton
Zhen Zhong Sapienza – Università di Roma
Preview of Salvatore Vultaggio - Space-like Infinity and Energy Densities in GR
Salvatore Vultaggio (U of Otago): Space-like Infinity and Energy Densities in GR
Jan. 12, 2026 10:30 — 11:00
Preview of Anil Colpan Zenginoglu - From Penrose to Melrose: Computing Scattering Amplitudes at Infinity
Anil Colpan Zenginoglu (U of Maryland): From Penrose to Melrose: Computing Scattering Amplitudes at Infinity
Jan. 12, 2026 11:30 — 12:00
Preview of Joerg Frauendiener - The geometry of null-infinity
Joerg Frauendiener (U of Otago): The geometry of null-infinity
Jan. 12, 2026 14:00 — 14:30
Preview of David Hilditch - Hyperboloidal Foliations and their Application
David Hilditch (IST Lisboa): Hyperboloidal Foliations and their Application
Jan. 12, 2026 16:00 — 16:30
Preview of Benjamin Leather - Gravitational self-force with hyperboloidal slicing
Benjamin Leather (U Southampton): Gravitational self-force with hyperboloidal slicing
Jan. 13, 2026 09:30 — 10:00
Preview of Marina De Amicis - Dynamical quasinormal mode excitation
Marina De Amicis (Perimeter Institute, Waterloo): Dynamical quasinormal mode excitation
Jan. 13, 2026 14:00 — 14:30
Preview of Patrick Bourg - Linear and nonlinear QNMs on a hyperboloidal slice
Patrick Bourg (Radboud U): Linear and nonlinear QNMs on a hyperboloidal slice
Jan. 13, 2026 14:30 — 15:00
Preview of Rodrigo Panosso Macedo - Exceptional Points and Resonance in Black Hole Ringdown
Rodrigo Panosso Macedo (NBI, Copenhagen): Exceptional Points and Resonance in Black Hole Ringdown
Jan. 13, 2026 15:00 — 15:30
Preview of Piotr T. Chruściel - On hyperbolic and holographic mass
Piotr T. Chruściel (U of Vienna): On hyperbolic and holographic mass
Jan. 14, 2026 11:00 — 11:30
Preview of Jose-Luis Jaramillo - Spectrum and evolution in black hole non-normal dynamics: the hyperboloidal key
Jose-Luis Jaramillo (U de Bourgogne, Dijon): Spectrum and evolution in black hole non-normal dynamics: the hyperboloidal key
Jan. 15, 2026 09:30 — 10:00
Preview of Pedro H. Croti Siqueira - Probing the unstable spectrum of Schwarzschild-like black holes
Pedro H. Croti Siqueira (UFABC, Santo André): Probing the unstable spectrum of Schwarzschild-like black holes
Jan. 15, 2026 11:00 — 11:30
Preview of Lucas T. de Paula - Pseudospectrum of rotating analog black holes
Lucas T. de Paula (UFABC, Santo André): Pseudospectrum of rotating analog black holes
Jan. 15, 2026 11:30 — 12:00
Preview of Alex Vañó Viñuales - Hyperboloidal strong field initial data and 3D progress with BSSN/Z4
Alex Vañó Viñuales (U de Les Illes Balears): Hyperboloidal strong field initial data and 3D progress with BSSN/Z4
Jan. 16, 2026 10:00 — 10:30
Preview of Shalabh Gautam - 3D Summation-By-Parts Schemes on Hyperboloidal Slices
Shalabh Gautam (BIMSA, Beijing): 3D Summation-By-Parts Schemes on Hyperboloidal Slices
Jan. 16, 2026 11:00 — 11:30
At a glance
Type:
Workshop
When:
Jan. 12, 2026 — Jan. 16, 2026
Where:
ESI Boltzmann Lecture Hall
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)
More:
Website