06.10.2021 (Wednesday)

Constructing the 6 Loop 4 Point N=4 super-Yang-Mills Integrand

Journal Club Alex Edison (Uppsala U.)

16:00 QMW
room G.O. Jones 610

In this talk, we'll discuss the current state-of-the-art for constructing multi-loop integrands in N=4 super-Yang-Mills. After briefly covering some of the key goals, background, and ideas behind the multiloop integrand program, we turn to the cutting edge: constructing the complete (planar and non-planar) integrand for the six-loop four-point amplitude in maximal $D\le10$ super-Yang-Mills. This construction employs new advances that combat the proliferation of loops and state-sums when evaluating multi-loop $D$-dimensional unitarity cuts. Concretely, it uses two graph-based approaches, applicable in a range of theories, to evaluating generalized unitarity cuts in $D$ dimensions: 1) recursively from lower-loop cuts, or 2) directly from known higher-loop planar cuts. Neither method relies on explicit state sums or any sewing of tree-level amplitudes. The first method meshes particularly well with the Method of Maximal Cuts to allow direct construction of the complete six-loop integrand.