English
Related papers

Related papers: Ehrhart positivity for lattice path matroids

200 papers

By the Choi matrix criteria it is easy to determine if a specific linear matrix map is completely positive, but to establish whether a linear matrix map is positive is much less straightforward. In this paper we consider classes of linear…

Functional Analysis · Mathematics 2021-03-29 Sanne ter Horst , Alma Naude

In 2004, Choe, Oxley, Sokal and Wagner established a tight connection between matroids and multiaffine real stable polynomials. Recently, Branden used this theory and a polynomial coming from the Vamos matroid to disprove the generalized…

Combinatorics · Mathematics 2014-11-11 Sam Burton , Cynthia Vinzant , Yewon Youm

We consider area preserving maps of surfaces and extend Mather's result on the equality of the closure of the four branches of saddles. He assumed elliptic fixed points to be Moser stable, while we require only that the derivative at this…

Dynamical Systems · Mathematics 2024-04-08 Fernando Oliveira , Gonzalo Contreras

There has been significant interest in studying the asymptotics of certain generalised moments, called the moments of moments, of characteristic polynomials of random Haar-distributed unitary and symplectic matrices, as the matrix size $N$…

Mathematical Physics · Physics 2023-04-21 Theodoros Assiotis , Edward Eriksson , Wenqi Ni

It is a famous open question whether every integrally closed reflexive polytope has a unimodal Ehrhart delta-vector. We generalize this question to arbitrary integrally closed lattice polytopes and we prove unimodality for the delta-vector…

Combinatorics · Mathematics 2011-10-18 Jan Schepers , Leen Van Langenhoven

There is a simple formula for the Ehrhart polynomial of a cyclic polytope. The purpose of this paper is to show that the same formula holds for a more general class of polytopes, lattice-face polytopes. We develop a way of decomposing any…

Combinatorics · Mathematics 2007-05-23 Fu Liu

We investigate the Ehrhart polynomial for the class of 0-symmetric convex lattice polytopes in Euclidean $n$-space $\mathbb{R}^n$. It turns out that the roots of the Ehrhart polynomial and Minkowski's successive minima are closely related…

Metric Geometry · Mathematics 2011-10-20 Martin Henk , Achill Schuermann , Joerg M. Wills

Efficient deterministic algorithms to construct representations of lattice path matroids over finite fields are presented. They are built on known constructions of hierarchical secret sharing schemes, a recent characterization of…

Combinatorics · Mathematics 2024-07-09 Carles Padró

Findings by M. L. Lyra, S. Mayboroda and M. Filoche relate invertibility and positivity of a class of discrete Schr\"odinger matrices with the existence of the "Landscape Function", which provides an upper bound on all eigenvectors…

Mathematical Physics · Physics 2020-01-30 John Buhl , Isaac Cinzori , Isabella Ginnett , Mark Landry , Yikang Li , Xingyan Liu

Schubert varieties of hyperplane arrangements, also known as matroid Schubert varieties, play an essential role in the proof of the Dowling-Wilson conjecture and in Kazhdan-Lusztig theory for matroids. We study these varieties as…

Algebraic Geometry · Mathematics 2023-06-30 Colin Crowley

We show Kantor's conjecture (1974) holds in rank 4. This proves both the sticky matroid conjecture of Poljak and Turzik (1982) and the whole Kantor's conjecture, due to an argument of Bachem, Kern, and Bonin, and an equivalence argument of…

Combinatorics · Mathematics 2021-08-11 Jaeho Shin

In this paper we present a definition of oriented Lagrangian symplectic matroids and their representations. Classical concepts of orientation and this extension may both be thought of as stratifications of thin Schubert cells into unions of…

Combinatorics · Mathematics 2007-05-23 Richard F. Booth , Alexandre V. Borovik , Israel M. Gelfand , Neil White

Let $ (E,h) $ be a Griffiths semipositive Hermitian holomorphic vector bundle of rank $ 3 $ over a complex manifold. In this paper, we prove the positivity of the characteristic differential form $ c_1(E,h) \wedge c_2(E,h) - c_3(E,h) $,…

Differential Geometry · Mathematics 2022-03-15 Filippo Fagioli

We prove the unimodality of the Ehrhart $\delta$-polynomial of the chain polytope of the zig-zag poset, which was conjectured by Kirillov. First, based on a result due to Stanley, we show that this polynomial coincides with the…

Combinatorics · Mathematics 2016-03-29 Herman Z. Q. Chen , Philip B. Zhang

This note generalizes a result contained in a previous paper [ J. Sanders, Circuit preserving edge maps II, J. Combin. Theory Ser. B 42 (1987), 146-155].

Combinatorics · Mathematics 2017-11-23 Jon Henry Sanders

We show that all finite lattices, including non-distributive lattices, arise as stable matching lattices when all agents have path-independent choice functions. This result answers an open question of Blair~\cite{blair1988lattice}. In the…

Discrete Mathematics · Computer Science 2026-04-09 Christopher En , Yuri Faenza

We generalize the well-studied notion of a modular pair of a finite matroid to arbitrary families of sets in infinite matroids, and use it to develop the theory of infinite matroids in several as-yet-unexplored areas. Our results include a…

Combinatorics · Mathematics 2026-04-23 Mattias Ehatamm , Peter Nelson , Fernanda Rivera Omana

Luis Ferroni and Alex Fink recently introduced a polytope of all unlabeled matroids of rank $r$ on $n$ elements, and they showed that the vertices of this polytope come from matroids that can be characterized by maximizing a sequence of…

Combinatorics · Mathematics 2025-12-23 Joseph E. Bonin

This paper investigates infinite matroids from a categorical perspective. We prove that the category of infinite matroids is a proto-exact category in the sense of Dyckerhoff and Kapranov, thereby generalizing our previous result on the…

Combinatorics · Mathematics 2021-09-01 Chris Eppolito , Jaiung Jun

We prove that the extension complexity of the independence polytope of every regular matroid on $n$ elements is $O(n^6)$. Past results of Wong and Martin on extended formulations of the spanning tree polytope of a graph imply a $O(n^2)$…

Combinatorics · Mathematics 2019-12-23 Manuel Aprile , Samuel Fiorini