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Scattering amplitudes from the canonical form of the amplituhedron

Show that in planar N=4 supersymmetric Yang–Mills theory, the n-point tree-level scattering amplitude equals the canonical form of the amplituhedron A_{k,n,m}(Z), and that the L-loop scattering amplitude equals the integral of an appropriate regulator function against the canonical form of the loop amplituhedron as defined by Arkani-Hamed and Trnka.

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Background

The amplituhedron framework proposes a geometric reformulation of scattering amplitudes in planar N=4 SYM, replacing sums over Feynman diagrams with canonical forms on positive geometries. At tree level, the conjecture posits an exact identification between the amplitude and the amplituhedron’s canonical form; at loop level, an integral over a regulator function against the canonical form of a loop amplituhedron is expected to reproduce the amplitude.

A proof would rigorously establish the amplituhedron as a complete geometric model for amplitudes, strengthening the link between positive geometry and quantum field theory computations.

References

The scattering amplitude is conjecturally obtained by the canonical form of the amplituhedron at tree-level, and as the integral over a regulator function against the canonical form of the amplituhedron at loop-level, see p.~17 for the definition of the loop amplituhedron.

Algebraic and Positive Geometry of the Universe: from Particles to Galaxies (2502.13582 - Fevola et al., 19 Feb 2025) in Section 5 (Interactions), paragraph on amplituhedra and amplitudes