Peeling the Gravitational Onion: Unraveling the Secrets of Newman–Penrose and Aretakis Constants
IFPU
May 18 – May 22, 2026
Over the past decades, advances in gravitational physics have revealed that null hypersurfaces harbor rich and unexpected structures, most notably hierarchies of conservation laws that appear without any evident underlying symmetry. Chief among these are the Newman-Penrose (NP) and Aretakis constants, associated with null infinity and extremal black hole horizons, respectively. Despite their robust mathematical formulation, their physical interpretation remains elusive. This workshop aims to bring together experts from theory and phenomenology of gravity to investigate these conservation laws, uncover their origins, and assess their physical implications. This workshop aims to bring together experts from theory, phenomenology, and observation to investigate these conservation laws, uncover their origins, and assess their potential observational signatures.
Meeting website:
Organisers:
- Simon Pekar (SISSA & INFN Trieste)
- Panagiotis Charalambous (SISSA & INFN Trieste)
Participants:
- Stefanos Aretakis (University of Toronto)
- Achilleas Porfyriadis (University of Crete)
- Marc Geiller (CNRS, ENS de Lyon)
- Celine Zwikel (Collège de France, Paris)
- Alexander Grant (University of Southampton)
- Geoffrey Compere (Université Libre de Bruxelles)
- Jibril Ben Achour (ENS de Lyon)
- David Kubiznak (Institute of Theoretical Physics, Charles University)
- Simone Speziale (CNRS, CPT Marseille)
- Aron Kovacs (Queen Mary University of London, School of Mathematical Sciences)
- Glenn Barnich (Université Libre de Bruxelles)
- Antonio Cristofaro (Sapienza Università di Roma & INFN Roma)
- Andrea Campoleoni (Université de Mons)