Exact BPS Couplings and Black Hole Counting

Duration: 58 mins 37 secs
Share this media item:
Embed this media item:


About this item
Description: Pioline, B
Tuesday 25th May 2021 - 14:30 to 15:30
 
Created: 2021-05-26 17:18
Collection: New connections in number theory and physics
Publisher: Isaac Newton Institute for Mathematical Sciences
Copyright: Pioline, B
Language: eng (English)
 
Abstract: In order to determine the exact spectrum of BPS states in four-dimensional string vacua with extended supersymmetry, a useful strategy is to consider certain BPS-saturated couplings in the low-energy effective action in three dimensions, after compactifying on a circle. These couplings are highly constrained by supersymmetry and dualities, and can sometimes be determined exactly. The BPS indices can then be read off from the Fourier expansion in the large radius limit. This strategy has been applied to the counting of 1/8-BPS (respectively 1/4, 1/2) states in string vacua with N=8 (respectively, 4,2) supersymmetry in four dimensions, leading to rather exotic types of automorphic functions from the point of view of mathematics, but quite natural from the point of view of physics. This includes theta liftings of genus two Siegel modular forms (in the N=8 and N=4 cases), as well as mock modular forms of higher depth (in the N=2 case, or in the closely related set up of N=4 super-Yang Mills theory).
Available Formats
Format Quality Bitrate Size
MPEG-4 Video 640x360    1.12 Mbits/sec 495.79 MB View Download
WebM 640x360    470.27 kbits/sec 201.96 MB View Download
iPod Video 480x270    479.54 kbits/sec 205.88 MB View Download
MP3 44100 Hz 249.77 kbits/sec 107.35 MB Listen Download
Auto * (Allows browser to choose a format it supports)