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Related papers: Tropical fans, scattering equations and amplitudes

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We introduce diagrams for $m$-cluster categories which we call "horizontal" and "vertical" mutation fans. These are analogous to the mutation fans (also known as "semi-invariant pictures" or "scattering diagrams") for the standard ($m=1$)…

Representation Theory · Mathematics 2018-05-18 Kiyoshi Igusa

The tropical variety defined by linear equations with constant coefficients is the Bergman fan of the corresponding matroid. Building on a self-contained introduction to matroid polytopes, we present a geometric construction of the Bergman…

Combinatorics · Mathematics 2007-05-23 Eva Maria Feichtner , Bernd Sturmfels

Recently, scattering amplitudes in four-dimensional Minkowski spacetime have been interpreted as conformal correlation functions on the two-dimensional celestial sphere, the so-called celestial amplitudes. In this note we consider…

High Energy Physics - Theory · Physics 2021-12-08 Livia Ferro , Robert Moerman

We extend tropicalization and tropical compactification of subvarieties of algebraic tori to subvarieties of spherical homogeneous spaces. Given a tropical compactification of a subvariety, we show that the support of the colored fan of the…

Algebraic Geometry · Mathematics 2020-08-31 Jenia Tevelev , Tassos Vogiannou

In this note I will explain how relative/log Gromov-Witten invariants of pairs $(X,D)$ with very ample smooth anticanonical divisor $D$ can be computed using algebro-combinatorial objects called scattering diagrams. The underlying principle…

Algebraic Geometry · Mathematics 2022-10-20 Tim Graefnitz

Motivated by the construction of Newton--Okounkov bodies and toric degenerations via cluster algebras in [GHKK18, FO25], we consider a family of Newton--Okounkov polytopes of a complex smooth Fano variety $X$ related by a composition of…

Symplectic Geometry · Mathematics 2025-08-07 Yunhyung Cho , Myungho Kim , Yoosik Kim , Euiyong Park

This paper demonstrates that the homogeneous coordinate ring of the Grassmannian $\Bbb{G}(k,n)$ is a {\it cluster algebra of geometric type} - as defined by S. Fomin and A. Zelevinsky. Grassmannians having {\it finite cluster type} are…

Combinatorics · Mathematics 2007-05-23 Joshua S. Scott

We study the relation between the integer tropical points of a cluster variety (satisfying the full Fock-Goncharov conjecture) and the totally positive part of the tropicalization of an ideal presenting the corresponding cluster algebra.…

Algebraic Geometry · Mathematics 2022-11-29 Lara Bossinger

We establish a direct connection between scattering amplitudes in planar four-dimensional theories and a remarkable mathematical structure known as the positive Grassmannian. The central physical idea is to focus on on-shell diagrams as…

We generalise the notion of Gr\"obner fan to ideals in R[[t]][x_1,...,x_n] for certain classes of coefficient rings R and give a constructive proof that the Gr\"obner fan is a rational polyhedral fan. For this we introduce the notion of…

Commutative Algebra · Mathematics 2018-08-24 Thomas Markwig , Yue Ren

We review recent progress in the understanding of symmetries for scattering amplitudes in N=4 superconformal Yang-Mills theory. It is summarized how the superficial breaking of superconformal symmetry by collinear anomalies and the…

High Energy Physics - Theory · Physics 2015-03-19 Till Bargheer , Niklas Beisert , Florian Loebbert

The scattering equations on the Riemann sphere give rise to remarkable formulae for tree-level gauge theory and gravity amplitudes. Adamo, Casali and Skinner conjectured a one-loop formula for supergravity amplitudes based on scattering…

High Energy Physics - Theory · Physics 2015-09-23 Yvonne Geyer , Lionel Mason , Ricardo Monteiro , Piotr Tourkine

We show that the half-integrands in the CHY representation of tree amplitudes give rise to the definition of differential forms -- the scattering forms -- on the moduli space of a Riemann sphere with $n$ marked points. These differential…

High Energy Physics - Theory · Physics 2018-04-04 Leonardo de la Cruz , Alexander Kniss , Stefan Weinzierl

In this paper, we classify singular real plane tropical curves by means of subdivisions of Newton polytopes. First, we introduce signed Bergman fans (generalizing positive Bergman fans from [AKW06]) that describe real tropicalizations of…

Algebraic Geometry · Mathematics 2018-02-07 Christian Jürgens

The map which takes a square matrix $A$ to its polytrope is piecewise linear. We show that cones of linearity of this map form a polytopal fan partition of $\{R}^{n \times n}$, whose face lattice is anti-isomorphic to the lattice of…

Combinatorics · Mathematics 2013-02-22 Ngoc M. Tran

We focus on the $G$-fans associated with cluster patterns whose initial exchange matrices are of infinite type. We study the asymptotic behavior of the $g$-vectors around the initial $G$-cone under the alternating mutations for two indices…

Combinatorics · Mathematics 2024-11-26 Tomoki Nakanishi

We give an explicit construction of the cluster scattering diagram for any acyclic exchange matrix of affine type. We show that the corresponding cluster scattering fan coincides both with the mutation fan and with a fan constructed in the…

Combinatorics · Mathematics 2025-08-04 Nathan Reading , Salvatore Stella

We advance the exploration of cluster-algebraic patterns in the building blocks of scattering amplitudes in $\mathcal{N}=4$ super Yang-Mills theory. In particular we conjecture that, given a maximal cut of a loop amplitude, Landau…

High Energy Physics - Theory · Physics 2020-05-15 Ömer Gürdoğan , Matteo Parisi

We associate a dimer algebra A to a Postnikov diagram D (in a disk) corresponding to a cluster of minors in the cluster structure of the Grassmannian Gr(k,n). We show that A is isomorphic to the endomorphism algebra of a corresponding…

Representation Theory · Mathematics 2020-12-21 Karin Baur , Alastair King , Bethany Marsh

In the cluster algebra literature, the notion of a graded cluster algebra has been implicit since the origin of the subject. In this work, we wish to bring this aspect of cluster algebra theory to the foreground and promote its study. We…

Rings and Algebras · Mathematics 2015-06-22 Jan E. Grabowski