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Related papers: Matroid polytopes, nested sets and Bergman fans

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We say that a tropical fan is homologically smooth if each of its open subsets verify tropical Poincare duality. A tropical homology manifold is a tropical variety that is locally modelled by open subsets of homologically smooth tropical…

Algebraic Geometry · Mathematics 2024-05-10 Omid Amini , Matthieu Piquerez

Alcoved polytopes are characterized by the property that all facet normal directions are parallel to the roots $e_i-e_j$. Unlike other prominent families of polytopes, like generalized permutahedra, alcoved polytopes are not closed under…

Combinatorics · Mathematics 2025-11-05 Nick Early , Lukas Kühne , Leonid Monin

This paper introduces Dirichlet matroids, a generalization of graphic matroids arising from electrical networks. We present four main theorems. First, we exhibit a matroid quotient involving geometric duals of networks embedded in surfaces…

Combinatorics · Mathematics 2022-06-02 Bob Lutz

The lattice of flats $\mathcal L_M$ of a matroid $M$ is combinatorially well-behaved and, when $M$ is realizable, admits a geometric model in the form of a "Schubert variety of hyperplane arrangement". In contrast, the lattice of flats of a…

Algebraic Geometry · Mathematics 2025-09-19 Colin Crowley , Connor Simpson , Botong Wang

We give a new proof of the fact that the complement of the complexification of a real hyperplane arrangement is homotopy equivalent to the Salvetti complex of the associated oriented matroid. Our proof involves no choices, is relatively…

Combinatorics · Mathematics 2025-07-10 Galen Dorpalen-Barry , Dan Dugger , Nicholas Proudfoot

We are interested in expanding our understanding of symplectic matroids by exploring the properties of a class of symplectic matroids with a "lattice of flats". Taking a well-behaved family of subdivisions of the cross polytope we obtain a…

Combinatorics · Mathematics 2026-01-08 Or Raz

We investigate geometric embeddings among several classes of stacky fans and algorithms, e.g., to compute their homology. Interesting cases arise from moduli spaces of tropical curves. Specifically, we show that the tropical honeycomb…

Combinatorics · Mathematics 2021-09-21 Dominic Bunnett , Michael Joswig , Julian Pfeifle

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

In the 1990s, Kita--Yoshida and Cho--Matsumoto introduced intersection forms on the twisted (co)homologies of hyperplane arrangement complements. We give a closed combinatorial formula for these intersection pairings. We show that these…

Combinatorics · Mathematics 2025-08-05 Thomas Lam

Credal sets are one of the most important models for describing probabilistic uncertainty. They usually arise as convex sets of probabilistic models compatible with judgments provided in terms of coherent lower previsions or more specific…

Probability · Mathematics 2022-09-28 Damjan Škulj

Suppose that X is a Fano manifold that corresponds under Mirror Symmetry to a Laurent polynomial f, and that P is the Newton polytope of f. In this setting it is expected that there is a family of algebraic varieties over the unit disc with…

Algebraic Geometry · Mathematics 2019-12-11 Tom Coates , Alessio Corti , Genival da Silva

In this paper, we introduce the notion of an admissible partition of a simplicial polyhedral fan and define the category of a partitioned fan as a generalisation of the $\tau$-cluster morphism category of a finite-dimensional algebra. This…

Representation Theory · Mathematics 2025-02-26 Maximilian Kaipel

We study the tropicalization of the variety of symmetric rank two matrices. Analogously to the result of Markwig and Yu for general tropical rank two matrices, we show that it has a simplicial complex structure as the space of symmetric…

Combinatorics · Mathematics 2025-04-21 May Cai , Kisun Lee , Josephine Yu

We associate to each toric vector bundle on a toric variety X(Delta) a "branched cover" of the fan Delta together with a piecewise-linear function on the branched cover. This construction generalizes the usual correspondence between toric…

Algebraic Geometry · Mathematics 2008-12-07 Sam Payne

The asymmetric tropical distance is a distance measure on the tropical torus $\mathbb{R}^n/\mathbb{R}\mathbf{1}$ and in particular on the Bergman fan $B(K_N) \subseteq \mathbb{R}^{\binom{N}{2}}/\mathbb{R}\mathbf{1}$ of the complete…

Combinatorics · Mathematics 2026-03-02 Fabian Lenzen , Lena Weis

We show that the tropical projective Grassmannian of planes is homeomorphic to a closed subset of the analytic Grassmannian in Berkovich's sense by constructing a continuous section to the tropicalization map. Our main tool is an explicit…

Algebraic Geometry · Mathematics 2014-03-12 Maria Angelica Cueto , Mathias Haebich , Annette Werner

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 utilize the coherent-constructible correspondence to construct full strongly exceptional collections of nef line bundles in the derived category of a toric variety through the combinatorics of constructible sheaves built from polytopes.…

Algebraic Geometry · Mathematics 2023-11-08 Mario Sanchez

The space T_{d,n} of n tropically collinear points in a fixed tropical projective space TP^{d-1} is equivalent to the tropicalization of the determinantal variety of matrices of rank at most 2, which consists of real d x n matrices of…

Combinatorics · Mathematics 2009-07-13 Hannah Markwig , Josephine Yu

We show how the Tutte polynomial of a matroid $M$ can be computed from its condensed configuration, which is a statistic of its lattice of cyclic flats. The results imply that the Tutte polynomial of $M$ is already determined by the…

Combinatorics · Mathematics 2014-09-26 Jens Niklas Eberhardt