N=4 SYM on K3 and the AdS(3)/CFT(2) Correspondence
  We study the Fareytail expansion of the topological partition function of N=4 SU(N) super Yang-Mills theory on K3. We argue that this expansion corresponds to a sum over geometries in asymptotically AdS_3 spacetime, which is holographically dual to a large number of coincident fundamental heterotic strings. 
Kazumi Okuyama