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We study determinantal varieties from conditional independence models with hidden variables, focusing on their irreducible decompositions, dimensions, degrees, and Gr\"obner bases. Each variety encodes a collection of matroids, whose flats…

Combinatorics · Mathematics 2026-01-22 Per Alexandersson , Yulia Alexandr , Emiliano Liwski , Fatemeh Mohammadi , Pardis Semnani

In 1997, Erd\H{o}s asked whether for arbitrarily large $n$ there exists a set of $n$ points in $\mathbb{R}^2$ that determines $O(\frac{n}{\sqrt{\log n}})$ distinct distances while satisfying the local constraint that every 4-point subset…

Combinatorics · Mathematics 2026-01-21 Benjamin Grayzel

We investigate overdetermined linear inverse problems for which the forward operator may not be given accurately. We introduce a new tool called the structure, based on the Wasserstein distance, and propose the use of this to diagnose and…

Numerical Analysis · Mathematics 2018-11-01 Michael A. Puthawala , Cory D. Hauck , Stanley J. Osher

In his seminal 1983 paper, Jim Lawrence introduced lopsided sets and featured them as asymmetric counterparts of oriented matroids, both sharing the key property of strong elimination. Moreover, symmetry of faces holds in both structures as…

Combinatorics · Mathematics 2018-01-04 Hans-Juergen Bandelt , Victor Chepoi , Kolja Knauer

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 give a deterministic polynomial time $2^{O(r)}$-approximation algorithm for the number of bases of a given matroid of rank $r$ and the number of common bases of any two matroids of rank $r$. To the best of our knowledge, this is the…

Data Structures and Algorithms · Computer Science 2018-11-06 Nima Anari , Shayan Oveis Gharan , Cynthia Vinzant

This paper considers an idempotent and symmetrical algebraic structure as well as some closely related concept. A special notion of determinant is introduced and a Cramer formula is derived for a class of limit systems derived from the…

Combinatorics · Mathematics 2020-10-09 Walter Briec

A sequence of approximations for the determinant and its logarithm of a complex matrixis derived, along with relative error bounds. The determinant approximations are derived from expansions of det(X)=exp(trace(log(X))), and they apply to…

Numerical Analysis · Mathematics 2011-05-04 Ilse C. F. Ipsen , Dean J. Lee

Erd\H{o}s conjectured in 1946 that every n-point set P in convex position in the plane contains a point that determines at least floor(n/2) distinct distances to the other points of P. The best known lower bound due to Dumitrescu (2006) is…

Computational Geometry · Computer Science 2013-03-25 Gabriel Nivasch , János Pach , Rom Pinchasi , Shira Zerbib

We give a quantum-inspired $O(n^4)$ algorithm computing the Tutte polynomial of a lattice path matroid, where $n$ is the size of the ground set of the matroid. Furthermore, this can be improved to $O(n^2)$ arithmetic operations if we…

Combinatorics · Mathematics 2015-10-08 Jason Morton , Jacob Turner

Consider a real hyperplane arrangement and let $\mathcal{C}$ denote the occurring chambers. Bidigare, Hanlon and Rockmore introduced a Markov chain on $\mathcal{C}$ which is a generalization of some card shuffling models used in computer…

Probability · Mathematics 2016-09-27 Evita Nestoridi

We explore a combinatorial theory of linear dependency in complex space, "complex matroids", with foundations analogous to those for oriented matroids. We give multiple equivalent axiomatizations of complex matroids, showing that this…

Combinatorics · Mathematics 2013-03-27 Laura Anderson , Emanuele Delucchi

We fix three natural numbers $k, n, N$, such that $n+k+1=N$, and introduce the notion of two dual arrangements of hyperplanes. One of the arrangements is an arrangement of $N$ hyperplanes in a $k$-dimensional affine space, the other is an…

Algebraic Geometry · Mathematics 2007-05-23 D. Mukherjee , A. Varchenko

We prove a discrete version of the first Weber inequality on three-dimensional hybrid spaces spanned by vectors of polynomials attached to the elements and faces of a polyhedral mesh. We then introduce two Hybrid High-Order methods for the…

Numerical Analysis · Mathematics 2021-10-26 Florent Chave , Daniele A. Di Pietro , Simon Lemaire

Extending the notion of geometric bijections for regular matroids, introduced by the first and third author with Matthew Baker, we describe a family of bijections between bases of an oriented matroid and special orientations. These…

Combinatorics · Mathematics 2026-04-07 Spencer Backman , Francisco Santos , Chi Ho Yuen

We introduce a construction of oriented matroids from a triangulation of a product of two simplices. For this, we use the structure of such a triangulation in terms of polyhedral matching fields. The oriented matroid is composed of…

Combinatorics · Mathematics 2020-10-26 Marcel Celaya , Georg Loho , Chi Ho Yuen

In this paper a new fast algorithm for the computation of the distance of a matrix to a nearby defective matrix is presented. The problem is formulated following Alam & Bora (Linear Algebra Appl., 396 (2005), pp.~273--301) and reduces to…

Numerical Analysis · Mathematics 2012-11-05 Melina A. Freitag , Alastair Spence

The Chow ring of a matroid (or more generally, atomic latice) is an invariant whose importance was demonstrated by Adiprasito, Huh and Katz, who used it to resolve the long-standing Heron-Rota-Welsh conjecture. Here, we make a detailed…

Combinatorics · Mathematics 2023-11-16 Thomas Hameister , Sujit Rao , Connor Simpson

The number-theoretic codes are a class of codes defined by single or multiple congruences and are mainly used for correcting insertion and deletion errors. Since the number-theoretic codes are generally non-linear, the analysis method for…

Information Theory · Computer Science 2021-02-02 Takayuki Nozaki

A matroid is a machine capturing linearity of mathematical objects and producing combinatorial structures. Matroid structure arises everywhere since linearity is a ubiquitous concept. One natural way to obtain matroids is by considering…

Combinatorics · Mathematics 2023-03-14 Jaeho Shin