Statut  Confirmé 
Série  IPHTMAT 
Domaines  hepth 
Date  Mercredi 19 Fevrier 2020 
Heure  14:15 
Institut  IPHT 
Salle  Salle Claude Itzykson, Bât. 774 
Nom de l'orateur  Geoffrey Compère 
Prenom de l'orateur  
Addresse email de l'orateur  
Institution de l'orateur  Université Libre de Bruxelles 
Titre  Some physics behind supertranslations and superrotations 
Résumé  I will first provide a birdeye view upon the infrared structure of gravity. I will shortly describe the relationship between BMS symmetry, soft theorems and memory effects at leading and subleading orders in the large radius expansion, while emphasizing the specificities of superLorentz symmetries. Secondly, I will present a nogo result on the soft hair conjecture: supertranslations induced by matter creating and falling inside black holes do not affect Hawking radiation, though they do affect scattering amplitudes. I will start by proving that Unruh radiation is unaffected by supertranslations induced by a shockwave and then show that Hawking radiation is mathematically related to this system, as a consequence of the principle of equivalence. Third, I will explain how BMS symmetry is associated to fluxbalance laws that provide constraints upon the motion of binary compact mergers. Finally, I will present the extension of the BMS group to asymptotically de Sitter spacetimes. 
Numéro de preprint arXiv  
Commentaires  
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