  In integrable quantum field theories the large volume spectrum is given by
the Bethe Ansatz. The leading corrections, due to virtual particles circulating
around the cylinder, are encoded in so-called Luscher corrections. In order to
apply these techniques to the AdS/CFT correspondence one has to generalize
these corrections to the case of generic dispersion relations and to
multiparticle states. We review these various generalizations and the
applications of Luscher's corrections to the study of the worldsheet QFT of the
superstring in AdS5xS5 and, consequently, to anomalous dimensions of operators
in N=4 SYM theory.
