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Related papers: Matroid polytopes, nested sets and Bergman fans

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We study moduli spaces of rational weighted stable tropical curves, and their connections with the classical Hassett spaces. Given a vector w of weights, the moduli space of tropical w-stable curves can be given the structure of a balanced…

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

The Lagrangian geometry of matroids was introduced in [ADH20] through the construction of the conormal fan of a matroid M. We used the conormal fan to give a Lagrangian-geometric interpretation of the h-vector of the broken circuit complex…

Combinatorics · Mathematics 2021-09-27 Federico Ardila , Graham Denham , June Huh

For any lattice congruence of the weak order on permutations, N. Reading proved that gluing together the cones of the braid fan that belong to the same congruence class defines a complete fan, called a quotient fan, and V. Pilaud and F.…

Combinatorics · Mathematics 2023-11-14 Arnau Padrol , Vincent Pilaud , Julian Ritter

We give an explicit description of the poset of cells of Bergman complexes of Lattice Path Matroids and establish a criterion for its simpliciality, in terms of the shape of the bounding paths.

Combinatorics · Mathematics 2015-08-21 Emanuele Delucchi , Martin Dlugosch

We introduce the conormal fan of a matroid M, which is a Lagrangian analog of the Bergman fan of M. We use the conormal fan to give a Lagrangian interpretation of the Chern-Schwartz-MacPherson cycle of M. This allows us to express the…

Combinatorics · Mathematics 2022-02-16 Federico Ardila , Graham Denham , June Huh

In hep-th/0111053, a complete simplicial fan was associated to an arbitrary finite root system. It was conjectured that this fan is the normal fan of a simple convex polytope (a generalized associahedron of the corresponding type). Here we…

Combinatorics · Mathematics 2007-05-23 Frederic Chapoton , Sergey Fomin , Andrei Zelevinsky

For a tensor triangulated category which is well generated in the sense of Neeman, it is shown that the collection of Bousfield classes forms a set. This set has a natural structure of a complete lattice which is then studied, using the…

Representation Theory · Mathematics 2012-05-15 Srikanth B. Iyengar , Henning Krause

We describe a family of tropical fans related to Grassmannian cluster algebras. These fans are related to the kinematic space of massless scattering processes in a number of ways. For each fan associated to the Grassmannian ${\rm Gr}(k,n)$…

High Energy Physics - Theory · Physics 2021-11-24 James Drummond , Jack Foster , Ömer Gürdoğan , Chrysostomos Kalousios

The image of the complement of a hyperplane arrangement under a monomial map can be tropicalized combinatorially using matroid theory. We apply this to classical moduli spaces that are associated with complex reflection arrangements.…

Algebraic Geometry · Mathematics 2014-10-28 Qingchun Ren , Steven V Sam , Bernd Sturmfels

We define Chern-Schwartz-MacPherson (CSM) cycles of an arbitrary matroid. These are balanced weighted fans supported on the skeleta of the corresponding Bergman fan. In the case that the matroid arises from a complex hyperplane arrangement…

Combinatorics · Mathematics 2019-08-14 Lucia Lopez de Medrano , Felipe Rincon , Kristin Shaw

The aim of this paper is to study homological properties of tropical fans and to propose a notion of smoothness in tropical geometry, which goes beyond matroids and their Bergman fans and which leads to an enrichment of the category of…

Algebraic Geometry · Mathematics 2021-05-05 Omid Amini , Matthieu Piquerez

For any lattice congruence of the weak order on $\mathfrak{S}_n$, N. Reading proved that glueing together the cones of the braid fan that belong to the same congruence class defines a complete fan. We prove that this fan is the normal fan…

Combinatorics · Mathematics 2019-06-04 Vincent Pilaud , Francisco Santos

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 study nested complexes of building sets on the Las Vergnas face lattices of oriented matroids. Such a nested complex is the face lattice of an oriented matroid, obtained by iterated stellar subdivisions of the positive tope. If the…

Combinatorics · Mathematics 2025-09-22 Chiara Mantovani , Arnau Padrol , Vincent Pilaud

For an arbitrary finite Coxeter group W we define the family of Cambrian lattices for W as quotients of the weak order on W with respect to certain lattice congruences. We associate to each Cambrian lattice a complete fan, which we…

Combinatorics · Mathematics 2026-05-13 Nathan Reading

We describe a canonical compactification of a polyhedral complex in Euclidean space. When the recession cones of the polyhedral complex form a fan, the compactified polyhedral complex is a subspace of a tropical toric variety. In this case,…

Algebraic Geometry · Mathematics 2020-12-23 Lars Kastner , Kristin Shaw , Anna-Lena Winz

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

In this paper, we continue our study of blade arrangements and the positroidal subdivisions which are induced by them on $\Delta_{k,n}$. A blade is a tropical hypersurface which is generated by a system of $n$ affine simple roots of type…

Combinatorics · Mathematics 2022-10-14 Nick Early

Triangulations of a product of two simplices and, more generally, of root polytopes are closely related to Gelfand-Kapranov-Zelevinsky's theory of discriminants, to tropical geometry, tropical oriented matroids, and to generalized…

Combinatorics · Mathematics 2018-03-19 Pavel Galashin , Gleb Nenashev , Alexander Postnikov

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