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A tale of two exponentiations in ${\cal N}=8$ supergravity
The structure of scattering amplitudes in supergravity theories continues to be of interest. Recently, the amplitude for 2→2 scattering in N=8 supergravity was presented at three-loop order for the first time. The result can be written in terms of an exponentiated one-loop contribution, modulo a rem...
Autores principales: | , , , , , |
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Lenguaje: | eng |
Publicado: |
2019
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1016/j.physletb.2019.134927 http://cds.cern.ch/record/2686818 |
Sumario: | The structure of scattering amplitudes in supergravity theories continues to be of interest. Recently, the amplitude for 2→2 scattering in N=8 supergravity was presented at three-loop order for the first time. The result can be written in terms of an exponentiated one-loop contribution, modulo a remainder function which is free of infrared singularities, but contains leading terms in the high energy Regge limit. We explain the origin of these terms from a well-known, unitarity-restoring exponentiation of the high-energy gravitational S -matrix in impact-parameter space. Furthermore, we predict the existence of similar terms in the remainder function at all higher loop orders. Our results provide a non-trivial cross-check of the recent three-loop calculation, and a necessary consistency constraint for any future calculation at higher loops. |
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