Four-point Amplitudes in N=8 Supergravity and Wilson Loops

dc.creatorBrandhuber, Andreas
dc.creatorHeslop, Paul
dc.creatorNasti, Adele
dc.creatorSpence, Bill
dc.creatorTravaglini, Gabriele
dc.date2008-05-19
dc.date2008-09-03
dc.date.accessioned2026-07-07T11:50:53Z
dc.date.available2026-07-07T11:50:53Z
dc.descriptionPrompted by recent progress in the study of N=4 super Yang-Mills amplitudes, and evidence that similar approaches might be relevant to N=8 supergravity, we investigate possible iterative structures and applications of Wilson loop techniques in maximal supergravity. We first consider the two-loop, four-point MHV scattering amplitude in N=8 supergravity, confirming that the infrared divergent parts exponentiate, and we give the explicit expression which represents the failure for this to occur for the finite part. We observe that each term in the expansion of the one- and two-loop amplitudes in the dimensional regularisation parameter epsilon has a uniform degree of transcendentality. We then turn to consider Wilson loops in supergravity, showing that a natural definition of the loop, involving the Christoffel connection, fails to reproduce the one-loop amplitude. An alternative expression, which involves the metric explicitly, is shown to have a close relationship with the physical amplitude. We find that in a gauge in which the cusp diagrams vanish, the remaining diagrams for this Wilson loop correctly generate the full one-loop, four-point N=8 supergravity amplitude.
dc.description32 pages, 4 figures. v2: typos corrected. v3: Clarifications added in section 3, typos fixed. Published version to appear in Nuclear Physics B
dc.identifierhttps://arxiv.org/abs/0805.2763
dc.identifierhttp://arxiv.org/abs/0805.2763
dc.identifierNucl.Phys.B807:290-314,2009
dc.identifierdoi:10.1016/j.nuclphysb.2008.09.010
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/203713
dc.subjectHigh Energy Physics - Theory
dc.titleFour-point Amplitudes in N=8 Supergravity and Wilson Loops
dc.typetext

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