BFKL Pomeron and Bern-Dixon-Smirnov amplitudes in N=4 SUSY

Abstract

We review the theoretical approaches for investigations of the high energy hadron-hadron scattering in the Regge kinematics. It is demonstrated, that the gluon in QCD is reggeized and the Pomeron is a composite state of the reggeized gluons. Remarkable properties of the BFKL equation for the Pomeron wave function in QCD and supersymmetric gauge theories are outlined. Due to the AdS/CFT correspondence the BFKL Pomeron is equivalent to the reggeized graviton in the extended N=4 SUSY. The properties of the maximal transcendentality and integrability are realized in this model. The BDS multi-gluon scattering amplitudes are investigated in the Regge limit. They do not contain the Mandelstam cuts and are not valid beyond one loop. It is shown, that the hamiltonian for these composite states coincides with the hamiltonian of an integrable open Heisenberg spin chain.