BMS-Supertranslation Charges at the Critical Sets of Null Infinity

Explore a 58-minute lecture on BMS-supertranslation charges at the critical sets of null infinity, delivered by Juan A. Valiente Kroon at the Erwin Schrödinger International Institute for Mathematics and Physics. Delve into the analysis of Strominger's conjecture for asymptotically flat spacetimes, which proposes a relationship between asymptotic BMS-supertranslations and their associated charges at past and future null infinity through an antipodal map at spatial infinity. Examine the validity of this conjecture using Friedrich's formulation of spatial infinity, which provides a regular initial value problem for conformal field equations. Discover how BMS-supertranslation charges are not well-defined at critical sets where null infinity meets spatial infinity for generic asymptotically Euclidean and regular initial data, unless an extra regularity condition is met. Learn how initial data satisfying the regularity condition fully determines BMS-supertranslation charges at critical sets, and understand the direct relationship between charges at past and future null infinity. Gain insights from this joint work with Mariem Magdy Ali Mohamed and Kartik Prabhu, presented as part of the Thematic Programme on "Carrollian Physics and Holography" at ESI in April 2024.