Café com Física



25 de fevereiro de 2015

Pedro Vieira
Perimeter Institute for Theoretical Physics

Scattering Amplitudes as a Flux-Tube Gas

I will survey recent progress in the quest for an exact formulation of gauge theories. I will describe recent progress in looking for a new description of Quantum Field Theory, based on so-called Integrability techniques, which bypasses the use of traditional Feynman diagram perturbative techniques and promises to greatly improve our understanding of finite coupling quantum fields. More precisely, we shall propose the first non-perturbative formulation of planar scattering amplitudes in a non-abelian Gauge theory (N=4 Super Yang-Mills Theory) or, equivalently, polygonal Wilson loops. The construction is based on the Operator Product Expansion approach and introduces a new decomposition of the Wilson loop in terms of fundamental building blocks named Pentagon transitions. These transitions satisfy a simple relation to the worldsheet S-matrix on top of the so called Gubser-Klebanov-Polyakov vacuum which allows us to bootstrap them at any value of the coupling.