In this talk, I will discuss recent results for three-loop QCD scattering amplitudes. After a quick and gentle review of the techniques that enabled our calculations, I will illustrate their relevance both for phenomenological studies and for refining our understanding of perturbative gauge theories. Specifically, I will discuss how the three-loop gg->γγ amplitude allowed us to obtain improved theoretical predictions relevant for bounding the Higgs-boson total width through interferometry, and how the three-loop amplitudes for parton-partons scattering helped to shed some light on the structure of all-order QCD in the high-energy, or Regge, regime.
Konstantin Asteriadis