Statut  Confirmé 
Série  COURS 
Domaines  astroph,grqc,hepth,mathph 
Date  Vendredi 3 Mai 2019 
Heure  10:00 
Institut  IPHT 
Salle  Salle Claude Itzykson, Bât. 774 
Nom de l'orateur  Nick Warner 
Prenom de l'orateur  
Addresse email de l'orateur  
Institution de l'orateur  USC and IPHT 
Titre  Black holes and microstate geometries (1/4) 
Résumé  The last few years have seen a remarkable shift in thinking about black holes and the information problem: There is a growing consensus that new physics must emerge at the horizon scale. Microstate Geometries provide the only classical mechanism that can evade a multitude of ``nogo'' theorems and actually support horizonscale structure. Such geometries are smooth, horizonless, solitonic solutions of massless supergravity that look just like black holes from far away but differ dramatically as one approaches the horizon scale. \par This course will examine supersymmetric ``blackholelike'' solutions of supergravity in various dimensions. \par We will start by constructing the simplest charged blackhole geometries, and will show how supersymmetry greatly simplifies the solutions, and the ``BPS equations'' that govern them. We will then use supersymmetry to construct multicentered BPS blackhole solutions. We will study the nearhorizon geometry and the tidal forces experienced by geodesic probes. \par To construct gravitational solitons, we will dissect one of the original ``no go'' theorems in fivedimensional gravity and show how ChernSimons interactions and magnetic fluxes threading nontrivial spatial topology provides a way around the standard dogma that there are ``no solitions without horizons''. In five dimensions, supersymmetry reduces the ``BPS equations'' to a linear ``electromagnetic problem'' and we will use this to construct large families of supersymmetric solitons in fivedimensional supergravity. We discuss the regularity and moduli spaces of such solutions. \par If there is sufficient time, we will survey an even richer classes of sixdimensional microstate geometries and discuss the tidal forces on geodesic probes. We will see that, unlike their blackhole counterparts, microstate geometries generate large tidal forces well before the probe reaches the horizon scale. This has very important implications for how infalling matter is ``scrambled'' by the black hole. 
Numéro de preprint arXiv  
Commentaires  https://courses.ipht.cnrs.fr/?q=en/node/227 
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