Superstrings on AdS_3 and Symmetric Products
  Some properties of N=2 superstrings on AdS_3 x N are studied. Their spectrum has the same pattern as 2-d CFTs in the moduli space of symmetric products M^p/S_p, where p is associated with the number of long fundamental strings required to construct the AdS_3 background, and M is the spacetime CFT corresponding to short string excitations of a single long string. Worldsheet operators associated with w long strings correspond to twisted sectors of M^p/S_p. 
Riccardo Argurio, Amit Giveon, Assaf Shomer