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Related papers: A tropical intersection product in matroidal fans

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We give an overview of recently implemented polymake features for computations in tropical geometry. The main focus is on explicit examples rather than technical explanations. Our computations employ tropical hypersurfaces, moduli of…

Algebraic Geometry · Mathematics 2018-10-30 Simon Hampe , Michael Joswig

We give a rigorous definition of tropical fans (the "local building blocks for tropical varieties") and their morphisms. For such a morphism of tropical fans of the same dimension we show that the number of inverse images (counted with…

Algebraic Geometry · Mathematics 2014-01-14 Andreas Gathmann , Michael Kerber , Hannah Markwig

We introduce a moduli functor for varieties whose tropicalization realizes a given weighted fan and show that this functor is an algebraic space in general, and is represented by a scheme of finite type when the associated toric variety is…

Algebraic Geometry · Mathematics 2012-03-30 Eric Katz , Sam Payne

This paper investigates isomorphisms of Bergman fans of matroids respecting different fan structures, which we regard as matroid analogs of birational maps. We show that isomorphisms respecting the fine fan structure are induced by matroid…

Algebraic Geometry · Mathematics 2022-07-28 Kris Shaw , Annette Werner

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

We provide some new local obstructions to approximating tropical curves in smooth tropical surfaces. These obstructions are based on the relation between tropical and complex intersection theories which is also established here. We give two…

Algebraic Geometry · Mathematics 2014-04-23 Erwan Brugalle , Kristin M. Shaw

We formulate a combinatorial version of the Intersection Hodge Conjecture for projective toric varieties. The conjecture asserts that the subspace of rational Hodge classes in the intersection cohomology $IH^*(X_\Sigma)$ is generated by the…

Algebraic Geometry · Mathematics 2025-12-09 Rizwan Jahangir

We study a particular graded ring structure on the set of all loopfree matroids on a fixed labeled ground set, which occurs naturally in tropical geometry. The product is given by matroid intersection and the additive structure is defined…

Combinatorics · Mathematics 2016-09-05 Simon Hampe

The real intersection cohomology of a toric variety is described in a purely combinatorial way using methods of elementary commutative algebra only. We define, for arbitrary fans, the notion of a ``minimal extension sheaf'' on the fan as an…

Algebraic Geometry · Mathematics 2009-10-31 Karl-Heinz Fieseler

In this paper, we consider weighted counts of tropical plane curves of particular combinatorial type through a certain number of generic points. We give a criterion, derived from tropical intersection theory on the secondary fan, for a…

Algebraic Geometry · Mathematics 2012-06-18 Eric Katz

We study the combinatorial properties of a tropical hyperplane arrangement. We define tropical oriented matroids, and prove that they share many of the properties of ordinary oriented matroids. We show that a tropical oriented matroid…

Combinatorics · Mathematics 2007-06-25 Federico Ardila , Mike Develin

We give a complete description of the cohomology ring $A^*(\overline Z)$ of a compactification of a linear subvariety $Z$ of a torus in a smooth toric variety whose fan $\Sigma$ is supported on the tropicalization of $Z$. It turns out that…

Algebraic Geometry · Mathematics 2016-12-01 Andreas Gross

We study representations of tropical linear spaces as intersections of tropical hyperplanes of circuits. For several classes of matroids, we describe minimal tropical bases. We also show that every realizable tropical linear space has a…

Combinatorics · Mathematics 2007-05-23 Josephine Yu , Debbie S. Yuster

In a previous work, we stated the conjecture that any semiring homomorphism between the Boolean function semirings on 1-dimensional tropical fans has the property called geometric. In this paper, we show that the conjecture is true. As an…

Algebraic Geometry · Mathematics 2024-08-23 Takaaki Ito

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

Tropical toric varieties are partial compactifications of finite dimensional real vector spaces associated with rational polyhedral fans. We introduce plurisubharmonic functions and a Bedford--Taylor product for Lagerberg currents on open…

Algebraic Geometry · Mathematics 2021-02-16 José Ignacio Burgos Gil , Walter Gubler , Philipp Jell , Klaus Künnemann

We study the fan structure of Dressians $\Dr(d,n)$ and local Dressians $\Dr(\cM)$ for a given matroid $\cM$. In particular we show that the fan structure on $\Dr(\cM)$ given by the three term Pl\"ucker relations coincides with the structure…

Combinatorics · Mathematics 2018-09-25 Jorge Alberto Olarte , Marta Panizzut , Benjamin Schröter

The main result of this paper is a formula for the limit cycle of a 1-parameter family of subvarieties of a tropical compactification, expressed in terms of tropical intersections. Our theorem generalizes results of…

Algebraic Geometry · Mathematics 2026-04-20 Sean T. Griffin , Jake Levinson , Rohini Ramadas , Rob Silversmith

Associated to any divisor in the Chow ring of a simplicial tropical fan, we construct a family of polytopal complexes, called normal complexes, which we propose as an analogue of the well-studied notion of normal polytopes from the setting…

Combinatorics · Mathematics 2023-03-14 Anastasia Nathanson , Dustin Ross

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