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Recently, an explicit, recursive formula for the all-loop integrand of planar scattering amplitudes in N=4 SYM has been described, generalizing the BCFW formula for tree amplitudes, and making manifest the Yangian symmetry of the theory.…

High Energy Physics - Theory · Physics 2015-05-20 Nima Arkani-Hamed , Jacob L. Bourjaily , Freddy Cachazo , Jaroslav Trnka

We show how to calculate the one-loop scattering amplitude with all gluons of negative helicity in non-supersymmetric Yang-Mills theory using MHV diagrams. We argue that the amplitude with all positive helicity gluons arises from a Jacobian…

High Energy Physics - Theory · Physics 2010-10-27 Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We propose a new diagrammatic formulation of the all-loop scattering amplitudes/Wilson loops in planar N=4 SYM, dubbed the "momentum-twistor diagrams". These are on-shell-diagrams obtained by gluing trivalent black and white vertices…

High Energy Physics - Theory · Physics 2015-06-22 Yuntao Bai , Song He

This article introduces a systematic framework to understand (not to derive yet) the all-loop 4-particle amplituhedron in planar N=4 SYM, utilizing both positivity and the Mondrian diagrammatics. Its key idea is the simplest one so far: we…

High Energy Physics - Theory · Physics 2020-06-23 Junjie Rao

In this paper, we study a new application of the positive Grassmanian to Wilson loop diagrams (or MHV diagrams) for scattering amplitudes in N=4 Super Yang-Mill theory ($N=4$ SYM). There has been much interest in studying this theory via…

Mathematical Physics · Physics 2016-07-20 Susama Agarwala , Eloi Marin Amat

We present new triangulations of the $m=4$ amplituhedron relevant for scattering amplitudes in planar $\mathcal{N}=4$ super-Yang-Mills, obtained directly from the combinatorial definition of the geometry. Using the "sign flip"…

High Energy Physics - Theory · Physics 2020-06-24 Ryota Kojima , Cameron Langer

We introduce and study the Wilson-loop ${\rm d}\log$ representation of certain Feynman integrals for scattering amplitudes in ${\cal N}=4$ SYM and beyond, which makes their evaluation completely straightforward. Such a representation was…

High Energy Physics - Theory · Physics 2021-05-26 Song He , Zhenjie Li , Yichao Tang , Qinglin Yang

Recent years have seen a surprising connection between the physics of scattering amplitudes and a class of mathematical objects--the positive Grassmannian, positive loop Grassmannians, tree and loop Amplituhedra--which have been loosely…

High Energy Physics - Theory · Physics 2017-12-06 Nima Arkani-Hamed , Yuntao Bai , Thomas Lam

All-loop planar scattering amplitudes in maximally supersymmetric Yang-Mills theory can be formulated geometrically in terms of the "amplituhedron". We study the mathematical structures of the one-loop amplituhedron, and present a new…

High Energy Physics - Theory · Physics 2016-02-17 Yuntao Bai , Song He , Thomas Lam

In this note we continue the exploration of the polytope picture for scattering amplitudes, where amplitudes are associated with the volumes of polytopes in generalized momentum-twistor spaces. After a quick warm-up example illustrating the…

High Energy Physics - Theory · Physics 2015-05-20 Nima Arkani-Hamed , Jacob L. Bourjaily , Freddy Cachazo , Andrew Hodges , Jaroslav Trnka

In this paper we define a new object, the momentum amplituhedron, which is the long sought-after positive geometry for tree-level scattering amplitudes in $\mathcal{N}=4$ super Yang-Mills theory in spinor helicity space. Inspired by the…

High Energy Physics - Theory · Physics 2019-09-04 David Damgaard , Livia Ferro , Tomasz Lukowski , Matteo Parisi

In this paper, we define the ABJM loop momentum amplituhedron, which is a geometry encoding ABJM planar tree-level amplitudes and loop integrands in the three-dimensional spinor helicity space. Translating it to the space of dual momenta…

High Energy Physics - Theory · Physics 2023-07-10 Tomasz Lukowski , Jonah Stalknecht

In this letter, we consider a positive geometry conjectured to encode the loop integrand of four-point stress-energy correlators in planar $\mathcal{N}=4$ super Yang-Mills. Beginning with four lines in twistor space, we characterize a…

High Energy Physics - Theory · Physics 2024-10-03 Song He , Yu-tin Huang , Chia-Kai Kuo

We study the symbol and the alphabet for two-loop NMHV amplitudes in planar ${\cal N}=4$ super-Yang-Mills from the $\bar{Q}$ equations, which provide a first-principle method for computing multi-loop amplitudes. Starting from one-loop…

High Energy Physics - Theory · Physics 2021-04-14 Song He , Zhenjie Li , Chi Zhang

We propose a geometrical approach to generate symbol letters of amplitudes/integrals in planar $\mathcal{N}=4$ Super Yang-Mills theory, known as {\it Schubert problems}. Beginning with one-loop integrals, we find that intersections of lines…

High Energy Physics - Theory · Physics 2022-09-07 Qinglin Yang

This article introduces a new approach to implement positivity for the 2-loop n-particle MHV amplituhedron, circumventing the conventional triangulation with respect to positive variables of each cell carved out by the sign flips. This…

High Energy Physics - Theory · Physics 2020-11-06 Ryota Kojima , Junjie Rao

In this paper, we take a major step towards the construction and applications of an all-loop, all-multiplicity amplituhedron for three-dimensional planar $\mathcal{N}=6$ Chern-Simons matter theory, or the $\textit{ABJM amplituhedron}$. We…

High Energy Physics - Theory · Physics 2023-09-26 Song He , Yu-tin Huang , Chia-Kai Kuo

We show how the MHV diagram description of Yang-Mills theories can be used to study non-supersymmetric loop amplitudes. In particular, we derive a compact expression for the cut-constructible part of the general one-loop MHV multi-gluon…

High Energy Physics - Theory · Physics 2010-12-14 James Bedford , Andreas Brandhuber , Bill Spence , Gabriele Travaglini

In this paper we study a relation between two positive geometries: the momentum amplituhedron, relevant for tree-level scattering amplitudes in $\mathcal{N} = 4$ super Yang-Mills theory, and the kinematic associahedron, encoding tree-level…

High Energy Physics - Theory · Physics 2021-02-24 David Damgaard , Livia Ferro , Tomasz Lukowski , Robert Moerman

We argue that the scattering amplitudes in the maximally supersymmetric N=4 super-Yang-Mills theory possess a new symmetry which extends the previously discovered dual conformal symmetry. To reveal this property we formulate the scattering…

High Energy Physics - Theory · Physics 2009-12-22 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev