The orthogonal momentum amplituhedron and ABJM amplitudes

Understand

In this paper, we introduce the momentum space amplituhedron for tree-level scattering amplitudes of ABJM theory.

• We demonstrate that the scattering amplitude can be identified as the canonical form on the space given by the product of positive orthogonal Grassmannian and the moment curve.
• The co-dimension one boundaries of this space are simply the odd-particle planar Mandelstam variables, while the even-particle counterparts are "hidden" as higher co-dimension boundaries.
• Remarkably, this space can be equally defined through a series of "sign flip" requirements of the projected external data, identical to "half" of four-dimensional $\mathcal{N}=4$ super Yang-Mills theory (sYM).