High Energy Theory Seminar

Scattering equations are useful in organizing perturbative S-matrix of massless particles. Based on these equations tree-level amplitudes admit a compact expression in theories such as pure Yang-Mills, gravity, etc, where properties such as unitarity and gauge invariance almost come for free. After reviewing the tree-level construction, I will show how to extend it to loop level by "hiding" pairs of particles, and discuss about the result thus obtained at one loop.