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Related papers: Matroidal Mixed Eulerian Numbers

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We derive explicit formulas for the matroidal mixed Eulerian numbers. We resolve a question posed by Berget, Spink, and Tseng, demonstrating that the invariant defined by matroidal mixed Eulerian numbers is precisely equivalent to Derksen's…

Algebraic Geometry · Mathematics 2025-02-10 Gaku Liu , Mateusz Michałek , Julian Weigert

In his study of generalised permutahedra, Postnikov considered the mixed volumes of hypersimplices, giving rise to the family of mixed Eulerian numbers. It comprises usual Eulerian numbers, binomial coefficients, Catalan numbers, and the…

Combinatorics · Mathematics 2024-11-07 Solal Gaudin

Remixed Eulerian numbers are a polynomial $q$-deformation of Postnikov's mixed Eulerian numbers. They arose naturally in previous work by the authors concerning the permutahedral variety and subsume well-known families of polynomials such…

Combinatorics · Mathematics 2022-09-20 Philippe Nadeau , Vasu Tewari

Motivated by recent work on (re)mixed Eulerian numbers, we provide a combinatorial interpretation of a subfamily of the remixed Eulerian numbers introduced by Nadeau and Tewari. More specifically, we show that these numbers can be realized…

Combinatorics · Mathematics 2025-09-03 Chao Xu , Jiang Zeng

In this paper we consider mixed volumes of combinations of hypersimplices. These numbers, called "mixed Eulerian numbers", were first considered by A. Postnikov and were shown to satisfy many properties related to Eulerian numbers, Catalan…

Combinatorics · Mathematics 2015-10-20 Gaku Liu

Let $\Phi$ be a root system. Postnikov introduced and studied the mixed $\Phi$-Eulerian numbers. These numbers indicate the mixed volumes of $\Phi$-hypersimplices. As specializations of these numbers, one can obtain the usual Eulerian…

Combinatorics · Mathematics 2023-03-14 Tatsuya Horiguchi

For any matroid $M$, we compute the Tutte polynomial $T_M(x,y)$ using the mixed intersection numbers of certain classes in the combinatorial Chow ring $A^\bullet(M)$ arising from hypersimplices. Using the mixed Hodge-Riemann relations, we…

Algebraic Geometry · Mathematics 2023-03-27 Andrew Berget , Hunter Spink , Dennis Tseng

Chow rings of toric varieties, which originate in intersection theory, feature a rich combinatorial structure of independent interest. We survey four different ways of computing in these rings, due to Billera, Brion, Fulton--Sturmfels, and…

Combinatorics · Mathematics 2024-01-17 Federico Ardila-Mantilla

Maxmin trees are labeled trees with the property that each vertex is either a local maximum or a local minimum. Such trees were originally introduced by Postnikov, who gave a formula to count them and different combinatorial interpretations…

Combinatorics · Mathematics 2019-02-06 William Dugan , Sam Glennon , Paul E. Gunnells , Einar Steingrimsson

Restricted Whitney numbers of the first kind appear in the combinatorial recursion for the matroid Kazhdan-Lusztig polynomials. In the special case of braid matroids (the matroid associated to the partition lattice, the complete graph, the…

Combinatorics · Mathematics 2018-02-06 Trevor K. Karn , Max D. Wakefield

We define a new family of generalized Stirling permutations that can be interpreted in terms of ordered trees and forests. We prove that the number of generalized Stirling permutations with a fixed number of ascents is given by a natural…

Combinatorics · Mathematics 2021-05-11 J. Fernando Barbero G. , Jesús Salas , Eduardo J. S. Villaseñor

We introduce the notion of sum-matroids and show its association with sum-rank metric codes. As a consequence, some results for sum-rank metric codes by Mart\'inez-Pe\~nas are generalized for sum-matroids. The sum-matroids generalize the…

Combinatorics · Mathematics 2022-03-23 Avijit Panja , Rakhi Pratihar , Tovohery Hajatiana Randrianarisoa

We use the geometry of the stellahedral toric variety to study matroids. We identify the valuative group of matroids with the cohomology ring of the stellahedral toric variety, and show that valuative, homological, and numerical equivalence…

Algebraic Geometry · Mathematics 2023-09-08 Christopher Eur , June Huh , Matt Larson

We introduce the Z-polynomial of a matroid, which we define in terms of the Kazhdan-Lusztig polynomial. We then exploit a symmetry of the Z-polynomial to derive a new recursion for Kazhdan-Lusztig coefficients. We solve this recursion,…

Combinatorics · Mathematics 2017-06-20 Nicholas Proudfoot , Ben Young , Yuan Xu

The volume and the number of lattice points of the permutohedron P_n are given by certain multivariate polynomials that have remarkable combinatorial properties. We give several different formulas for these polynomials. We also study a more…

Combinatorics · Mathematics 2007-05-23 Alexander Postnikov

Article presents a short investigation into some properties of the Moser polynomials which appear in various problems from algebraic combinatorics. For instance, these polynomials can be used to solve the Generalized Moser's Problem on…

Combinatorics · Mathematics 2019-03-12 Dmitri Fomin

We provide explicit combinatorial formulas for the Chow polynomial and for the augmented Chow polynomial of uniform matroids, thereby proving a conjecture by Ferroni. These formulas refine existing formulas by Hampe and by Eur, Huh, and…

Combinatorics · Mathematics 2024-12-02 Elena Hoster

Motivated by the question of whether Chow polynomials of matroids have only real roots, this article revisits the known relationship between Eulerian polynomials and the Hilbert series of Chow rings of permutohedral varieties. This is done…

Combinatorics · Mathematics 2024-10-21 Basile Coron

We study the Hilbert series of four objects arising in the Chow-theoretic and Kazhdan-Lusztig framework of matroids. These are, respectively, the Hilbert series of the Chow ring, the augmented Chow ring, the intersection cohomology module,…

Combinatorics · Mathematics 2024-06-05 Luis Ferroni , Jacob P. Matherne , Matthew Stevens , Lorenzo Vecchi

Binomial-Eulerian polynomials were introduced by Postnikov, Reiner and Williams. In this paper, properties of the binomial-Eulerian polynomials, including recurrence relations and generating functions are studied. We present three…

Combinatorics · Mathematics 2017-11-29 Jun Ma , Shi-Mei Ma , Yeong-Nan Yeh
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