Gluon scattering amplitudes/Wilson loops duality in N=4 SYM

by Emery Sokatchev (LAPP, Annecy)

Monday 19 Nov 2007, 14:00 → 15:30 Europe/Zurich

TH Theory Conference Room (CERN)

We review some aspects of the BDS conjecture about MHV gluon amplitudes and of the recently proposed string dual of Alday and Maldacena. The latter can be assimilated to a Wilson loop with light-like separated cusps. We show that most of the known properties of the MHV gluon amplitudes can be explained by conformal invariance. On the MHV side, this is a mysterious property of the multiloop Feynman integrals constituing the amplitude. On the Wilson loop side, the conformal symmetry is manifest, but broken by divergences. We formulate and study the corresponding anomalous Ward identities. They completely fix the form of the 4- and 5- gluon amplitudes, but leave room for an arbitrary function of conformal invariants for 6 or more gluons