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We show that maximal families of mutually unbiased bases are characterized in all dimensions by partitioned unitary error bases, up to a choice of a family of Hadamards. Furthermore, we give a new construction of partitioned unitary error…

Quantum Physics · Physics 2017-10-20 Benjamin Musto

Seymour's Splitter Theorem is a basic inductive tool for dealing with $3$-connected matroids. This paper proves a generalization of that theorem for the class of $2$-polymatroids. Such structures include matroids, and they model both sets…

Combinatorics · Mathematics 2017-06-27 James Oxley , Charles Semple , Geoff Whittle

In this paper we prove that the Stanley--Reisner ideal or cover ideal $I$ of a matroid is minimally resolvable by iterated mapping cones. As a technical tool for this purpose, we introduce and study focal matroids, which are submatroids of…

Commutative Algebra · Mathematics 2026-03-25 Paolo Mantero , Vinh Nguyen

We conjecture that it is not possible to finitely axiomatize matroid representability in monadic second-order logic for matroids, and we describe some partial progress towards this conjecture. We present a collection of sentences in monadic…

Combinatorics · Mathematics 2016-02-16 Dillon Mayhew , Mike Newman , Geoff Whittle

The notion of branch-depth for matroids was introduced by DeVos, Kwon and Oum as the matroid analogue of the tree-depth of graphs. The contraction-deletion-depth, another tree-depth like parameter of matroids, is the number of recursive…

Combinatorics · Mathematics 2024-02-27 Marcin Briański , Daniel Kráľ , Kristýna Pekárková

We define a matroid invariant called the three-cosystole that is related to higher notions of cogirth for weighted matroids, and we prove an optimal upper bound for it in the class of regular matroids of rank at most six. To accomplish…

Combinatorics · Mathematics 2026-05-21 James Dylan Douthitt , Elana Israel , Lee Kennard

We introduce the minor-closed, dual-closed class of multi-path matroids. We give a polynomial-time algorithm for computing the Tutte polynomial of a multi-path matroid, we describe their basis activities, and we prove some basic structural…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin , Omer Gimenez

Let $M$ be a matroid on a set $E$ and let $w:E\longrightarrow G$ be a weight function, where $G$ is a cyclic group. Assuming that $w(E)$ satisfies the Pollard's Condition (i.e. Every non-zero element of $w(E)-w(E)$ generates $G$), we obtain…

Combinatorics · Mathematics 2009-03-05 Y. O. Hamidoune , I. P. da Silva

One of the most intriguing unsolved questions of matroid optimization is the characterization of the existence of $k$ disjoint common bases of two matroids. The significance of the problem is well-illustrated by the long list of conjectures…

Combinatorics · Mathematics 2020-02-19 Kristóf Bérczi , Tamás Schwarcz

Motivated by Gr\"obner basis theory for finite point configurations, we define and study the class of "standard complexes" associated to a matroid. Standard complexes are certain subcomplexes of the independence complex that are invariant…

Combinatorics · Mathematics 2019-11-28 Alexander Engström , Raman Sanyal , Christian Stump

The growth-rate function for a minor-closed class $\mathcal{M}$ of matroids is the function $h$ where, for each non-negative integer $r$, $h(r)$ is the maximum number of elements of a simple matroid in $\mathcal{M}$ with rank at most $r$.…

Combinatorics · Mathematics 2016-04-18 Peter Nelson

Let $M$ be an arbitrary matroid with circuits $\mathcal{C}(M)$. We propose a definition of a derived matroid $\delta M$ that has as its ground set $\mathcal{C}(M)$. Unlike previous attempts of such a definition, our definition applies to…

Combinatorics · Mathematics 2022-12-22 Olga Kuznetsova , Ragnar Freij-Hollanti , Relinde Jurrius

Expansive polynomials (whose roots are greater than 1 in modulus) often arise in dynamical systems and other computational problems. This paper examines the expansivity gap (the gap between 1 and the smallest modulus of the roots) of these…

Number Theory · Mathematics 2020-11-09 M. J. Uray

We introduce a new width parameter for matroids called decomposition width and prove that every matroid property expressible in the monadic second order logic can be computed in linear time for matroids with bounded decomposition width if…

Discrete Mathematics · Computer Science 2009-04-21 Daniel Kral

We claim that $M$(atroid) theory may provide a mathematical framework for an underlying description of $M$-theory. Duality is the key symmetry which motivates our proposal. The definition of an oriented matroid in terms of the Farkas…

High Energy Physics - Theory · Physics 2008-11-26 J. A. Nieto

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

The classes of even-cycle matroids, even-cycle matroids with a blocking pair, and even-cut matroids each have hundreds of excluded minors. We show that the number of excluded minors for these classes can be drastically reduced if we…

Combinatorics · Mathematics 2020-06-02 Kevin Grace , Stefan H. M. van Zwam

We provide evidence for five long-standing, basis-exchange conjectures for matroids by proving them for the enormous class of sparse paving matroids. We also explore the role that these matroids may play in the following problem: as a…

Combinatorics · Mathematics 2010-11-05 Joseph E. Bonin

A class of matroids is introduced which is very large as it strictly contains all paving matroids as special cases. As their key feature these split matroids can be studied via techniques from polyhedral geometry. It turns out that the…

Combinatorics · Mathematics 2018-07-02 Michael Joswig , Benjamin Schröter

Let b(M) denote the maximal number of disjoint bases in a matroid M. It is shown that if M is a matroid of rank d+1, then for any continuous map f from the matroidal complex M into the d-dimensional Euclidean space there exist t \geq…

Combinatorics · Mathematics 2016-11-29 Imre Bárány , Gil Kalai , Roy Meshulam