English
Related papers

Related papers: Paving matroids that are not sparse paving

200 papers

We give new characterizations for the class of uniformly dense matroids and study applications of these characterizations to graphic and real representable matroids. We show that a matroid is uniformly dense if and only if its base polytope…

Combinatorics · Mathematics 2026-02-03 Karel Devriendt , Raffaella Mulas

We study varieties associated to hypergraphs from the point of view of projective geometry and matroid theory. We describe their decompositions into matroid varieties, which may be reducible and can have arbitrary singularities by the…

Combinatorics · Mathematics 2025-12-18 Oliver Clarke , Kevin Grace , Fatemeh Mohammadi , Harshit J Motwani

Well-known conjectures of Charney--Davis, Gal, and Nevo--Petersen predict increasingly strong positivity phenomena for the h-vectors of flag simplicial spheres. In this paper, we formulate and prove matroid analogues of these conjectures in…

Combinatorics · Mathematics 2026-04-24 Basile Coron , Luis Ferroni , Shiyue Li

The mutually enriching relationship between graphs and matroids has motivated discoveries in both fields. In this paper, we exploit the similar relationship between embedded graphs and delta-matroids. There are well-known connections…

Combinatorics · Mathematics 2019-03-04 Carolyn Chun , Iain Moffatt , Steven D. Noble , Ralf Rueckriemen

We investigate an approach to matroid complexity that involves describing a matroid via a list of independent sets, bases, circuits, or some other family of subsets of the ground set. The computational complexity of algorithmic problems…

Combinatorics · Mathematics 2007-09-10 Dillon Mayhew

Sparse linear regression is one of the most basic questions in machine learning and statistics. Here, we are given as input a design matrix $X \in \mathbb{R}^{N \times d}$ and measurements or labels ${y} \in \mathbb{R}^N$ where ${y} = {X}…

Machine Learning · Computer Science 2025-11-11 Gautam Chandrasekaran , Raghu Meka , Konstantinos Stavropoulos

We revisit the asymptotic analysis of probabilistic construction of adjacency matrices of expander graphs proposed in [4]. With better bounds we derived a new reduced sample complexity for the number of nonzeros per column of these…

Information Theory · Computer Science 2018-05-17 Bubacarr Bah , Jared Tanner

We study the random planar maps obtained from supercritical Galton--Watson trees by adding the horizontal connections between successive vertices at each level. These are the hyperbolic analog of the maps studied by Curien, Hutchcroft and…

Probability · Mathematics 2019-09-30 Thomas Budzinski

We show that, if $M$ is a simple rank-$n$ matroid with no $\ell$-point line minor and no minor isomorphic to the cycle matroid of a $t$-vertex complete graph, then the ratio $|M| / n$ is bounded above by a singly exponential function of…

Combinatorics · Mathematics 2023-06-28 Peter Nelson , Sergey Norin , Fernanda Rivera Omana

Basic path-matchings, introduced by Cunningham and Geelen (FOCS 1996), are a common generalization of matroid intersection and non-bipartite matching. The main results of this paper are a new algebraic characterization of basic…

Data Structures and Algorithms · Computer Science 2007-05-23 Nicholas J. A. Harvey

The classical matrix tree theorem relates the number of spanning trees of a connected graph with the product of the nonzero eigenvalues of its Laplacian matrix. The class of regular matroids generalizes that of graphical matroids, and a…

Combinatorics · Mathematics 2014-05-12 Aaron Dall , Julian Pfeifle

We introduce an algorithm for efficiently representing convolution with zero-padding and stride as a sparse transformation matrix, applied to a vectorized input through sparse matrix-vector multiplication (SpMV). We provide a theoretical…

Machine Learning · Computer Science 2024-12-02 Zan Chaudhry

We show for each positive integer $a$ that, if $\mathcal{M}$ is a minor-closed class of matroids not containing all rank-$(a+1)$ uniform matroids, then there exists an integer $c$ such that either every rank-$r$ matroid in $\mathcal{M}$ can…

Combinatorics · Mathematics 2013-06-04 Peter Nelson

We combine some known results and techniques with new ones to show that there exists a non-algebraic, multi-linear matroid. This answers an open question by Matus (Discrete Mathematics 1999), and an open question by Pendavingh and van Zwam…

Combinatorics · Mathematics 2016-07-01 Aner Ben-Efraim

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

Pairwise Markov Random Fields (MRFs) or undirected graphical models are parsimonious representations of joint probability distributions. Variables correspond to nodes of a graph, with edges between nodes corresponding to conditional…

Statistics Theory · Mathematics 2018-09-18 Eric Janofsky

Polymatroids can be considered as "fractional matroid" where the rank function is not required to be integer valued. Many, but not every notion in matroid terminology translates naturally to polymatroids. Defining cyclic flats of a…

Combinatorics · Mathematics 2019-10-15 Laszlo Csirmaz

We prove that for every proper minor-closed class $M$ of matroids representable over a prime field, there exists a constant-competitive matroid secretary algorithm for the matroids in $M$. This result relies on the extremely powerful…

Combinatorics · Mathematics 2019-10-03 Tony Huynh , Peter Nelson

In this paper we investigate a family of matroids introduced by Ardila and Billey to study one-dimensional intersections of complete flag arrangements of $\mathbb{C}^n$. The set of lattice points $P_n$ inside the equilateral triangle $S_n$…

Combinatorics · Mathematics 2018-11-20 Felix Gotti , Harold Polo

Many important enumerative invariants of a matroid can be obtained from its Tutte polynomial, and many more are determined by two stronger invariants, the $\mathcal{G}$-invariant and the configuration of the matroid. We show that the same…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin , Kevin Long