Séminaire de Physique Théorique

BMS algebra and supertranslation-invariant Lorentz charges

by Prof. Marc Henneaux (Intl. Solvay Inst., Brussels, College de France, U. Brussels)

Salle 1180, bâtiment E2 (Salle des séminaires )

Salle 1180, bâtiment E2

Salle des séminaires


The BMS algebra implies the puzzling feature that the standard  Lorentz charges are not invariant under BMS supertranslations.  This makes the definitions of the angular momentum and angular momentum flux somewhat obscure.  We provide a definition of the Lorentz charges that is supertranslation invariant.  In order to preserve a full canonical structure, it is necessary to introduce logarithmic BMS supertranslations.   Also to be pointed out is that the required redefinitions turn out to be non linear.