Abstract
We initiate an exploration of the physics and geometry of the amplituhedron, starting with the simplest case of the integrand for four-particle scattering in planar \( \mathcal{N}=4 \) SYM. We show how the textbook structure of the unitarity double-cut follows from the positive geometry. We also use the geometry to expose the behavior of the multicollinear limit, providing a direct motivation for studying the logarithm of the amplitude. In addition to computing the two and three-loop integrands, we explore various lower-dimensional faces of the amplituhedron, thereby computing non-trivial cuts of the integrand to all loop orders.
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ArXiv ePrint: 1312.7878
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Arkani-Hamed, N., Trnka, J. Into the amplituhedron. J. High Energ. Phys. 2014, 182 (2014). https://doi.org/10.1007/JHEP12(2014)182
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DOI: https://doi.org/10.1007/JHEP12(2014)182