Counterterms in N=8 Supergravity

          @misc{ scivideos_PIRSA:11010081,
            doi = {10.48660/11010081},
            url = {https://pirsa.org/11010081},
            author = {Kiermaier, Michael},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {Counterterms in N=8 Supergravity},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2011},
            month = {jan},
            note = {PIRSA:11010081 see, \url{https://scivideos.org/index.php/pirsa/11010081}}
          }
          

Abstract

N=8 supergravity in 4 dimensions exhibits a surprisingly favorable UV behavior -- it is known from explicit computations that the 4-point amplitudes in N=8 supergravity are finite up to 4-loop order. I explain how a "matrix-element approach" can be used to study candidate counterterms for UV divergences in this theory. This approach both demystifies the finiteness found in previous computations, and predicts finiteness of arbitrary n-point amplitudes in N=8 supergravity below the 7-loop order. It also points to the 7-loop 4-point amplitude as the first amplitude whose finiteness is not guaranteed by any known symmetry of the theory.