English
Related papers

Related papers: Internal boundaries of the loop amplituhedron

200 papers

Motivated by a new term-wise factorised formula for the two-loop MHV integrand for scattering amplitudes in $\mathcal{N}=4$ super Yang-Mills (SYM), together with recent results for the five-point negative ladders in loop space, we present…

High Energy Physics - Theory · Physics 2024-11-25 Ross Glew , Tomasz Lukowski

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

The amplituhedron is a semialgebraic set given as the image of the non-negative Grassmannian under a linear map subject to a choice of additional parameters. We define the limit amplituhedron as the limit of amplituhedra by sending one of…

Algebraic Geometry · Mathematics 2025-01-15 Joris Koefler , Rainer Sinn

Perturbative scattering amplitudes in gauge theories have remarkable simplicity and hidden infinite dimensional symmetries that are completely obscured in the conventional formulation of field theory using Feynman diagrams. This suggests…

High Energy Physics - Theory · Physics 2015-06-18 Nima Arkani-Hamed , Jaroslav Trnka

We present evidence that loop amplitudes in maximally supersymmetric $\mathcal{N}=4$ Yang-Mills (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the…

High Energy Physics - Theory · Physics 2015-01-07 Nima Arkani-Hamed , Jacob L. Bourjaily , Freddy Cachazo , Jaroslav Trnka

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

This thesis investigates geometric descriptions of scattering amplitudes, with a specific focus on scattering amplitudes in N=4 SYM and ABJM theory. The recent development of the field of positive geometries provides us with a suitable…

High Energy Physics - Theory · Physics 2024-09-25 Jonah Stalknecht

We investigate how the positive geometry framework for loop integrands in $\mathcal{N}{=}4$ super Yang-Mills theory constrains the structure of the integrated answers. This is done in the context of a geometric expansion of Wilson loops…

High Energy Physics - Theory · Physics 2025-08-08 Dmitry Chicherin , Johannes Henn , Elia Mazzucchelli , Jaroslav Trnka , Qinglin Yang , Shun-Qing Zhang

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…

High Energy Physics - Theory · Physics 2022-02-09 Yu-tin Huang , Ryota Kojima , Congkao Wen , Shun-Qing Zhang

We define a new geometry obtained from the all-loop amplituhedron in ${\cal N}=4$ SYM by reducing its four-dimensional external and loop momenta to three dimensions. Focusing on the simplest four-point case, we provide strong evidence that…

High Energy Physics - Theory · Physics 2023-01-19 Song He , Chia-Kai Kuo , Zhenjie Li , Yao-Qi Zhang

We give an explicit recursive formula for the all L-loop integrand for scattering amplitudes in N=4 SYM in the planar limit, manifesting the full Yangian symmetry of the theory. This generalizes the BCFW recursion relation for tree…

High Energy Physics - Theory · Physics 2011-01-17 Nima Arkani-Hamed , Jacob L. Bourjaily , Freddy Cachazo , Simon Caron-Huot , Jaroslav Trnka

The definition of the amplituhedron in terms of sign flips involves both one-loop constraints and the "mutual positivity" constraint. To gain an understanding of the all-loop integrand of $\mathcal{N}=4$ sYM requires understanding the…

High Energy Physics - Theory · Physics 2019-05-01 Cameron Langer , Akshay Yelleshpur Srikant

In this letter we compute a canonical set of cuts of the integrand for MHV amplitudes in planar ${\cal N}=4$ SYM, where all internal propagators are put on-shell. These "deepest cuts" probe the most complicated Feynman diagrams and on-shell…

High Energy Physics - Theory · Physics 2019-02-13 Nima Arkani-Hamed , Cameron Langer , Akshay Yelleshpur Srikant , Jaroslav Trnka

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

We present an ansatz for the planar five-loop four-point amplitude in maximally supersymmetric Yang-Mills theory in terms of loop integrals. This ansatz exploits the recently observed correspondence between integrals with simple conformal…

High Energy Physics - Theory · Physics 2008-11-26 Z. Bern , J. J. M. Carrasco , H. Johansson , D. A. Kosower

We extend the applications of prescriptive unitarity beyond the planar limit to provide local, polylogarithmic, integrand-level representations of six-particle MHV scattering amplitudes in both maximally supersymmetric Yang-Mills theory and…

High Energy Physics - Theory · Physics 2021-06-01 Jacob L. Bourjaily , Enrico Herrmann , Cameron Langer , Andrew J. McLeod , Jaroslav Trnka

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 initiate a comprehensive investigation of the geometry of the amplituhedron, a recently found geometric object whose volume calculates the integrand of scattering amplitudes in planar N=4 SYM theory. We do so by introducing and studying…

High Energy Physics - Theory · Physics 2014-08-18 Sebastian Franco , Daniele Galloni , Alberto Mariotti , Jaroslav Trnka

It has been a long-standing challenge to define a canonical loop integrand for non-supersymmetric gluon scattering amplitudes in the planar limit. Naive integrands are inflicted with $1/0$ ambiguities associated with tadpoles and massless…

High Energy Physics - Theory · Physics 2025-05-02 Nima Arkani-Hamed , Qu Cao , Jin Dong , Carolina Figueiredo , Song He

We present new, fundamentally combinatorial and topological characterizations of the amplituhedron. Upon projecting external data through the amplituhedron, the resulting configuration of points has a specified (and maximal) generalized…

High Energy Physics - Theory · Physics 2018-02-14 Nima Arkani-Hamed , Hugh Thomas , Jaroslav Trnka