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The tropical variety of a $d$-dimensional prime ideal in a polynomial ring with complex coefficients is a pure $d$-dimensional polyhedral fan. This fan is shown to be connected in codimension one. We present algorithmic tools for computing…

Algebraic Geometry · Mathematics 2009-12-16 Tristram Bogart , Anders Jensen , David Speyer , Bernd Sturmfels , Rekha Thomas

We use tropical and nonarchimedean geometry to study the moduli space of genus $0$ stable maps to $\mathbb{P}^1$ relative to two points. This space is exhibited as a tropical compactification in a toric variety. Moreover, the fan of this…

Algebraic Geometry · Mathematics 2017-06-06 Renzo Cavalieri , Hannah Markwig , Dhruv Ranganathan

We prove that the Chow ring of any simplicial fan is isomorphic to the middle degree part of the tropical cohomology ring of its canonical compactification. Using this result, we prove a tropical analogue of Kleiman's criterion of ampleness…

Algebraic Geometry · Mathematics 2024-05-09 Omid Amini , Matthieu Piquerez

We investigate the tropical analogues of totally positive and totally nonnegative matrices. These arise when considering the images by the nonarchimedean valuation of the corresponding classes of matrices over a real nonarchimedean valued…

Commutative Algebra · Mathematics 2019-12-30 Stéphane Gaubert , Adi Niv

Recent developments in particle physics have revealed deep connections between scattering amplitudes and tropical geometry. From the heart of this relationship emerged the chirotropical Grassmannian $\text{Trop}^\chi \text{G}(k,n)$ and the…

Combinatorics · Mathematics 2025-11-25 Dario Antolini , Nick Early

The purpose of this article is to study the role of Artin fans in tropical and non-Archimedean geometry. Artin fans are logarithmic algebraic stacks that can be described completely in terms of combinatorial objects, so called Kato stacks,…

Algebraic Geometry · Mathematics 2018-12-27 Martin Ulirsch

The Dressian Dr(k,n) parametrizes all tropical linear spaces, and it carries a natural fan structure as a subfan of the secondaryfan of the hypersimplex \Delta(k,n). We explore the combinatorics of the rays of Dr(k,n), that is, the most…

Combinatorics · Mathematics 2015-03-19 Sven Herrmann , Michael Joswig , David Speyer

We show that the algebraic invariants multiplicity and depth of a graded ideal in the polynomial ring are closely connected to the fan structure of its generic tropical variety in the constant coefficient case. Generically the multiplicity…

Commutative Algebra · Mathematics 2021-05-18 Tim Roemer , Kirsten Schmitz

We address the appearance of algebraic singularities in the symbol alphabet of scattering amplitudes in the context of planar $\mathcal{N}=4$ super Yang-Mills theory. We argue that connections between cluster algebras and tropical geometry…

High Energy Physics - Theory · Physics 2019-12-19 James Drummond , Jack Foster , Ömer Gürdoğan , Chrysostomos Kalousios

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

Tropical varieties play an important role in algebraic geometry. The Bergman complex B(M) and the positive Bergman complex B+(M) of an oriented matroid M generalize to matroids the notions of the tropical variety and positive tropical…

Combinatorics · Mathematics 2007-05-23 Federico Ardila , Victor Reiner , Lauren Williams

Given a closed subvariety of an algebraic torus, the associated tropical variety is a polyhedral fan in the space of 1-parameter subgroups of the torus which describes the behaviour of the subvariety at infinity. We show that the link of…

Algebraic Geometry · Mathematics 2010-03-16 Paul Hacking

The $g$-fan of a finite dimensional algebra is a fan in its real Grothendieck group defined by tilting theory. We give a classification of complete $g$-fans of rank 2. More explicitly, our first main result asserts that every complete…

Representation Theory · Mathematics 2023-05-24 Toshitaka Aoki , Akihiro Higashitani , Osamu Iyama , Ryoichi Kase , Yuya Mizuno

Let G be a simple and simply-connected complex algebraic group, and let X \subset G^\vee be the centralizer subgroup of a principal nilpotent element. Ginzburg and Peterson independently related the ring of functions on X with the homology…

Representation Theory · Mathematics 2012-04-26 Thomas Lam , Konstanze Rietsch

Tropical algebraic geometry is the geometry of the tropical semiring $(\mathbb{R},\min,+)$. Its objects are polyhedral cell complexes which behave like complex algebraic varieties. We give an introduction to this theory, with an emphasis on…

Algebraic Geometry · Mathematics 2007-05-23 Jürgen Richter-Gebert , Bernd Sturmfels , Thorsten Theobald

Let $G$ be a connected reductive algebraic group over an algebraically closed field of characteristic zero carrying the trivial valuation. In this article we discuss two candidates for what could be the tropicalization of $G$. Our first…

Algebraic Geometry · Mathematics 2025-03-28 Desmond Coles , Martin Ulirsch

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

Given two tropical polynomials $f, g$ on $\mathbb{R}^n$, we provide a characterization for the existence of a factorization $f= h \odot g$ and the construction of $h$. As a ramification of this result we obtain a parallel result for the…

Combinatorics · Mathematics 2019-08-02 Robert Alexander Crowell

In this paper we propose a general functorial definition of the operation of \emph{local tropicalization} in commutative algebra. Let $R$ be a commutative ring, $\Gamma$ a finitely generated subsemigroup of a lattice, $\gamma : \Gamma…

Algebraic Geometry · Mathematics 2015-03-20 Patrick Popescu-Pampu , Dmitry Stepanov

We define and study the cyclic Bergman fan of a matroid M, which is a simplicial polyhedral fan supported on the tropical linear space T(M) of M and is amenable to computational purposes. It slightly refines the nested set structure on…

Combinatorics · Mathematics 2013-03-07 Felipe Rincón