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SUMMARY:On the shoulders of giants: the cosmology of giant gravitons - Jef
 f Murugan (U. Cape Town)
DTSTART:20071107T141500Z
DTEND:20071107T153000Z
UID:TALK8858@talks.cam.ac.uk
CONTACT:Daniel Wesley
DESCRIPTION:The idea of mirage cosmology - the cosmological evolution indu
 ced on the worldvolume of a probe D-brane geodesically falling in some amb
 ient spacetime - is quite \nan appealing one\, at least from the point of 
 view of string-cosmological model building. In this talk\, I review the mi
 rage cosmology of a closed D3-brane wrapping the 3-sphere in the AdS part 
 of AdS_{5} \\times S^{5} and show that when this D3-brane is a giant gravi
 ton\, the resulting cosmology on the giant worldvolume is static. Unlike t
 he Einstein static universe of GR though\, this solution is not unstable t
 o homogeneous perturbations. On the other hand\, AdS giants are known to e
 xhibit an instability due to the emission of closed strings. Using some re
 cently developed technology for computing correlators of giant gravitons i
 n the dual N=4 SYM\, I show how this instability may be understood as grav
 itational radiation from the D-brane and interpreted in the cosmological c
 ontext. 
LOCATION:MR2\, Centre for Mathematical Sciences
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