The geometry of null-infinity

Joerg Frauendiener (U of Otago)

Jan 12. 2026, 14:00 — 14:30

The concept of null-infinity was formulated by R. Penrose in 1962 in order to give a geometric description of asymptotically flat space-times. Since then, this idea has been fundamental in many applications of general relativity, not the least being the rigorous definitions of gravitational radiation and global quantities, such as energy-momentum and angular momentum. In this talk, I will present a different view on the (degenerate) geometric structure of null-infinity, which draws attention to the idea of a cut-system. The interplay between a cut-system and conformal invariance is explored leading to an invariant definition of a Minkowski space-time "at infinity". Some consequences of this structure will be discussed.

 

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 Vienna)
Rodrigo Panosso Macedo (NBI, Copenhagen)
Alex Vañó Viñuales (U de Les Illes Balears)
Anil Colpan Zenginoglu (U of Maryland)