Gauge Theory Bootstrap.

We propose the gauge theory bootstrap, a method to compute the pion S matrix that describes the low-energy physics of the strong interaction and other similar gauge theories. The phase shifts of the S0, P1, and S2 waves obtained are in good agreement with experimental results. The only numerical inputs are the quark mass m_{q}, the QCD scale Λ_{QCD}, the pion mass m_{π}, and the pion decay constant f_{π} without any other experimental data.

Spin chains and string theory.

Recently, an important test of the anti de Sitter/conformal field theory correspondence has been done using rotating strings with two angular momenta. We show that such a test can be described more generally as the agreement between two actions: one a low energy description of a spin chain appearing in the field theory side, and the other a limit of the string action in AdS5xS5. This gives a map between the mean value of the spin in the boundary theory and the position of the string in the bulk, and shows how a string action can emerge from a gauge theory in the large-N limit.