Seminario
"Matching the Hagedorn Temperature in AdS/CFT"
Relatore: Dr. Marta Orselli NorditaNiels Bohr Institute, Copenhagen Note: Seminario teorico
Aula Feynman
17 Aprile 2007 ore 15.30
Abstract

We match the Hagedorn/deconfinement temperature of planar N=4 SYM on RXS^3 to the Hagedorn temperature of string theory on AdS_5XS^5. The matching is realized in a nearcritical region where both gauge theory and string theory are weakly coupled. The nearcritical region is near a point with zero temperature and critical chemical potential. On the gauge theory side we are taking a decoupling limit found in hepth/0605234 in which the physics of planar N = 4 SYM is given exactly by the ferromagnetic XXX1/2 Heisenberg spinchain. We find moreover a general relation between theHagedorn/deconfinement temperature and the thermodynamics of the Heisenberg spin chain and we use this to compute it in two distinct regimes. On the string theory side, we identify the dual limit. This
limit is taken of string theory on a maximally supersymmetric ppwave background with a flat direction, obtained from a Penrose limit of AdS_5 × S^5. We compute the Hagedorn temperature of the string theory and find
agreement with the Hagedorn/deconfinement temperature computed on the gauge theory side.


