PIRSA:21100005

Sequential Discontinuities of Scattering Amplitudes

APA

Sigridar Hannesdottir, H. (2021). Sequential Discontinuities of Scattering Amplitudes. Perimeter Institute. https://pirsa.org/21100005

MLA

Sigridar Hannesdottir, Hofie. Sequential Discontinuities of Scattering Amplitudes. Perimeter Institute, Oct. 12, 2021, https://pirsa.org/21100005

BibTex

          @misc{ pirsa_PIRSA:21100005,
            doi = {10.48660/21100005},
            url = {https://pirsa.org/21100005},
            author = {Sigridar Hannesdottir, Hofie},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Sequential Discontinuities of Scattering Amplitudes},
            publisher = {Perimeter Institute},
            year = {2021},
            month = {oct},
            note = {PIRSA:21100005 see, \url{https://pirsa.org}}
          }
          

Hofie Sigridar Hannesdottir Institute for Advanced Study (IAS)

Abstract

In this talk, we explore new techniques to probe the analytic structure of scattering amplitudes in perturbative Quantum Field Theory. The goal of this approach is to leverage symmetries, limits, and analyticity in order to circumvent the explicit evaluation of multi-loop Feynman integrals. First, we generalize the cutting rules by relating sequential discontinuities (discontinuities of discontinuities) to multiple cuts through the corresponding Feynman diagram. Then, we determine the logarithmic branch-cut structure of massive scattering amplitudes by expanding around their branch points. As a corollary, we prove a conjectured bound on the transcendental weight of polylogarithmic Feynman integrals. These results pave a new path towards bootstrapping scattering amplitudes in perturbation theory.