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CATEGORIES:Quantum Fields and Strings Seminars
SUMMARY:Exotic Branes and 3D Supergravity - Daniel Mayers
on (Amsterdam)
DTSTART;TZID=Europe/London:20141009T130000
DTEND;TZID=Europe/London:20141009T140000
UID:TALK54892AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/54892
DESCRIPTION:String theory has been known for quite a while to
contain non-perturbative objects called D-branes i
n addition to the fundamental strings the theory i
s named after. However\, fairly recently\, new typ
es of membranes in string theory are being studied
with increasing interest: the so-called "exotic b
ranes" (also known by other names). These exotic b
ranes have the interesting feature that their spac
etime is multi-valued or non-geometric\; this mean
s that when you travel in a circle around the bran
e\, the resulting spacetime looks different from t
hat which you started out with!\nIt is of consider
able interest to study and classify the possible t
ypes of such exotic branes that can exist in strin
g theory. To study them\, we can work in a 3D theo
ry (of maximal supergravity)\, where the exotic br
anes are just point particles. In this theory\, we
can at least classify the supersymmetric point pa
rticles\, thereby gaining insight into what kind o
f supersymmetric exotic branes exist in string the
ory. This problem reduces to that of classifying n
ilpotent orbits associated with the U-duality grou
p (E_8)\, for which various mathematical results a
re known. It can be shown that the only allowed su
persymmetric configurations are 1/2\, 1/4\, 1/8\,
and 1/16 BPS\, and their respective nilpotent orbi
ts can be given explicitly. On the other hand\, it
turns out exceedingly difficult to translate this
classification into a simple criterion for supers
ymmetry in terms of the non-Abelian (monodromy) ch
arges of the objects.
LOCATION:Potter Room (first floor\, Pav. B)
CONTACT:Godazgar
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