BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Exotic Branes and 3D Supergravity  - Daniel Mayerson (Amsterdam)
DTSTART:20141009T120000Z
DTEND:20141009T130000Z
UID:TALK54892@talks.cam.ac.uk
CONTACT:Godazgar
DESCRIPTION:String theory has been known for quite a while to contain non-
 perturbative objects called D-branes in addition to the fundamental string
 s the theory is named after. However\, fairly recently\, new types of memb
 ranes in string theory are being studied with increasing interest: the so-
 called "exotic branes" (also known by other names). These exotic branes ha
 ve the interesting feature that their spacetime is multi-valued or non-geo
 metric\; this means that when you travel in a circle around the brane\, th
 e resulting spacetime looks different from that which you started out with
 !\nIt is of considerable interest to study and classify the possible types
  of such exotic branes that can exist in string theory. To study them\, we
  can work in a 3D theory (of maximal supergravity)\, where the exotic bran
 es are just point particles. In this theory\, we can at least classify the
  supersymmetric point particles\, thereby gaining insight into what kind o
 f supersymmetric exotic branes exist in string theory. This problem reduce
 s to that of classifying nilpotent orbits associated with the U-duality gr
 oup (E_8)\, for which various mathematical results are known. It can be sh
 own that the only allowed supersymmetric configurations are 1/2\, 1/4\, 1/
 8\, and 1/16 BPS\, and their respective nilpotent orbits can be given expl
 icitly. On the other hand\, it turns out exceedingly difficult to translat
 e this classification into a simple criterion for supersymmetry in terms o
 f the non-Abelian (monodromy) charges of the objects. 
LOCATION:Potter Room (first floor\, Pav. B)
END:VEVENT
END:VCALENDAR