The study of the worldsheet S-matrix for AdS_5×S^5
strings was a key step in
the complete determination of the non-pertubrative planar
spectrum of anomalous
dimensions for N=4 super-Yang-Mills. To go beyond
the spectral problem it is
important to consider higher-point
worldsheet correlation functions and, as is
standard in many integrable models, one approach is
the study of form factors.
We will discuss a set of consistency conditions appropriate
to form factors in
the light-cone gauge
fixed AdS_5×S^5 string theory. We further
discuss the
form factors in the weakly coupled dual description,
verifying that the relevant conditions naturally hold for the one-loop Heisenberg
spin-chain.
