Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Di Vecchia, Paolo, Luna, Andrés, Naculich, Stephen G., Russo, Rodolfo, Veneziano, Gabriele, White, Chris D.
Lenguaje:eng
Publicado: 2019
Materias:
Acceso en línea:https://dx.doi.org/10.1016/j.physletb.2019.134927
http://cds.cern.ch/record/2686818
Descripción
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.