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Upcoming Seminars in series RENCTHEO  
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Thursday 19 December 2019, 10:00 at IHP, Salle 314  RENCTHEO (Rencontres Théoriciennes)  hepth 



Abstract:  I will prove a theorem about 2D CFTs: Every unitary 2D CFT must contain a nontrivial Virasoro primary of scaling dimension at most c/8 + 1/2, where c is the central charge. At large c, this is an improvement of the Hellerman bound c/6 + O(1), and is relevant for constraining the spectrum of gravitational theories in AdS3. The proof follows from the modular bootstrap and uses analytic extremal functionals, originally developed in the context of fourpoint SL(2) conformal bootstrap. In the second part of the talk, I will discuss a surprising connection between modular bootstrap and the spherepacking problem from discrete geometry. In particular, the above bound on the gap becomes a bound on the spherepacking density. In 8 and 24 dimensions, this bound is sharp and leads to a solution of the spherepacking problem in these dimensions, as originally proved by Viazovska et al. 
Thursday 9 January 2020, 10:00 at IHP, 314  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 9 January 2020, 11:40 at IHP, 314  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 23 January 2020, 10:00 at LPTHE, LPTHE Library  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 23 January 2020, 11:40 at LPTHE, bibliothèque du LPTHE, tour 1314, 4eme étage  RENCTHEO (Rencontres Théoriciennes)  hepth 



Abstract:  (based on 1906.09228 ) 
Thursday 6 February 2020, 10:00 at LPTHE, LPTHE Library  RENCTHEO (Rencontres Théoriciennes)  hepth 



Abstract:  TBA 
Thursday 6 February 2020, 11:40 at LPTHE, LPTHE Library  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 12 March 2020, 10:00 at IHP, 314  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 23 April 2020, 10:00 at IHP, 314  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 14 May 2020, 10:00 at IHP, 314  RENCTHEO (Rencontres Théoriciennes)  hepth 


Thursday 18 June 2020, 10:00 at IHP, 201  RENCTHEO (Rencontres Théoriciennes)  hepth 



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