Maths HEP Lunchtime Seminars: From correlators to Wilson loops and amplitudes
8 October 2010 13:00 in CM107 (note: non-standard room!)
We discuss a class of n-point correlation functions of 1/2 BPS operators in N=4 super Yang-Mills theory in four dimensions. Since this is a massless theory the question is best discussed in configuration space. For generic positions of the operators these correlation functions are finite.
We give a summary of recent work on the leading singular behaviour in a limit in which the positions are taken to be successively light-like separated. In dimensional regularisation or with a mass regulator the correlation functions reduce to polygonal Wilson loops with light-like edges.
A useful technical tool is to compute the correlators by insertions of the N=2 Yang-Mills Lagrangian, in which case it is particularly simple to take the light-like limit. If in a non-standard version of dimensional regularisation only the dimension of the integration measure at the insertion points is modified, we reproduce scattering amplitudes instead.
The integrand obtained in this way exactly agrees with a recent proposal by Arkani-Hamed et al.