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Related papers: Tropical ideals do not realise all Bergman fans

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To each prime ideal in a polynomial ring over a field we associate an algebraic matroid and show that it is preserved under tropicalization. This gives a necessary condition for a tropical variety to be set-theoretically realizable from a…

Combinatorics · Mathematics 2016-08-12 Josephine Yu

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

The Bergman fan of a matroid is the intersection of tropical hyperplanes defined by the circuits. A tropical basis is a subset of the circuits set that defines the Bergman fan. Yu and Yuster posed a question whether every simple regular…

Combinatorics · Mathematics 2019-02-22 Yasuhito Nakajima

We introduce and study a special class of ideals, called tropical ideals, in the semiring of tropical polynomials, with the goal of developing a useful and solid algebraic foundation for tropical geometry. The class of tropical ideals…

Algebraic Geometry · Mathematics 2019-02-20 Diane Maclagan , Felipe Rincón

We study a notion of tropical linear series on metric graphs that combines two essential properties of tropicalizations of linear series on algebraic curves: the Baker-Norine rank and the independence rank. Our main results relate the local…

Algebraic Geometry · Mathematics 2025-09-05 Chih-Wei Chang , Matthew Dupraz , Hernan Iriarte , David Jensen , Dagan Karp , Sam Payne , Jidong Wang

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 dissimilarity map $\delta$ on finite set $X$, the set of ultrametrics (equidistant tree metrics) which are $l^\infty$-nearest to $\delta$ is a tropical polytope. We give an internal description of this tropical polytope which we use…

Combinatorics · Mathematics 2019-12-24 Daniel Irving Bernstein

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

In this note, we characterize the products of simplicial generators for the Chow ring of a loopless matroid, extending a result of Backman, Eur, and Simpson. We prove that the stable intersection of a collection of tropical hyperplanes…

Combinatorics · Mathematics 2024-02-21 Calum Buchanan , Richard Danner

A "tropical ideal" is an ideal in the idempotent semiring of tropical polynomials that is also, degree by degree, a tropical linear space. We introduce a construction based on transversal matroids that canonically extends any principal…

Algebraic Geometry · Mathematics 2024-05-28 Alex Fink , Jeffrey Giansiracusa , Noah Giansiracusa , Joshua Mundinger

We prove that the proper amalgam of matroids $M_1$ and $M_2$ along their common restriction $N$ exists if and only if the tropical fibre product of Bergman fans ${B(M_1) \times_{B(N)} B(M_2)}$ is positive. We introduce tropical…

Algebraic Geometry · Mathematics 2024-04-30 Dmitry Mineev

Tropical ideals, introduced in arXiv:1609.03838, define subschemes of tropical toric varieties. We prove that the top-dimensional parts of their varieties are balanced polyhedral complexes of the same dimension as the ideal. This means that…

Algebraic Geometry · Mathematics 2020-10-01 Diane Maclagan , Felipe Rincón

We prove that the number of tropical critical points of an affine matroid (M,e) is equal to the beta invariant of M. Motivated by the computation of maximum likelihood degrees, this number is defined to be the degree of the intersection of…

Combinatorics · Mathematics 2024-07-23 Federico Ardila-Mantilla , Christopher Eur , Raul Penaguiao

In tropical algebraic geometry, the solution sets of polynomial equations are piecewise-linear. We introduce the tropical variety of a polynomial ideal, and we identify it with a polyhedral subcomplex of the Grobner fan. The tropical…

Algebraic Geometry · Mathematics 2007-05-23 David Speyer , Bernd Sturmfels

An affine tropical fan is called regular if it supports a reduced 0-dimensional complete intersection. For some cases the classification of regular fans is already complete. It was proved by Fink that tropical varieties of degree 1 are…

Combinatorics · Mathematics 2025-12-19 Linxuan Li

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

Let E be a plane in an algebraic torus over an algebraically closed field. Given a balanced 1-dimensional fan C in the tropicalization of E, i.e. in the Bergman fan of the corresponding matroid, we give a complete algorithmic answer to the…

Algebraic Geometry · Mathematics 2013-07-23 Andreas Gathmann , Kirsten Schmitz , Anna Lena Winstel

Describing the combinatorial structure of the tropical complex $C$ of a tropical matroid polytope, we obtain a formula for the coarse types of the maximal cells of $C$. Due to the connection between tropical complexes and resolutions of…

Combinatorics · Mathematics 2010-12-16 Katja Kulas

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

In classical geometry, a linear space is a space that is closed under linear combinations. In tropical geometry, it has long been a consensus that tropical varieties defined by valuated matroids are the tropical analogue of linear spaces.…

Algebraic Geometry · Mathematics 2015-05-11 Simon Hampe
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