Strings on AdS_3 x S^3 and the Plane-Wave Limit. Issues on PP-Wave/CFT   Holography
  In this thesis we give explicit results for bosonic string amplitudes on AdS_3 x S^3 and the corresponding plane-wave limit. We also analyze the consequences of our approach for understanding holography in this set up, as well as its possible generalization to other models. 
Oswaldo Zapata (Rome U., Tor Vergata & INFN, Rome2)