Séminaire de Physique Théorique
Simplifying (super-)BMS algebrasOscar Fuentealba (Université libre de Bruxelles, Belgique)
Thursday 01 February 2024 14:00 - Salle des séminaires - Salle 1180, bâtiment E2
Résumé :
In this talk, we will start with a brief review of the asymptotic structure of General Relativity from a Hamiltonian perspective and then show how the Henneaux-Troessaert asymptotic conditions can be relaxed so as to accommodate logarithmic deformations in the metric fall-off at spatial infinity. This implies a consistent enlargement of the BMS symmetry, with a new kind of "logarithmic supertranslations". The form of this new log-BMS algebra allows us to consistently decouple all supertranslations from the Lorentz generators. By following a similar mechanism, we will show that the nonlinear BMS algebra in 5D and the super-BMS algebra in 4D can be both redefined so as to take a direct sum structure. We will also explain the structure and charge-integrability of asymptotic symmetries with symmetry parameters depending on the fields (through the charges themselves), a topic relevant for nonlinear asymptotic symmetry algebras.
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