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Related papers: $k$-fold circuits and coning in rigidity matroids

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Motivated by the characterization of the lattice of cyclic flats of a matroid, the convolution of a ranked lattice and a discrete measure is defined, generalizing polymatroid convolution. Using the convolution technique we prove that if a…

Combinatorics · Mathematics 2019-10-03 Laszlo Csirmaz

For a smooth manifold X of dimension <d we construct a homomorphism from the algebraic K-theory group in degree d of the algebra of smooth functions on X to the degree -d-1 topological K-theory of X with coefficients in C/Z. This map…

K-Theory and Homology · Mathematics 2014-12-09 Ulrich Bunke

A well-known conjecture states that the Whitney numbers of the second kind of a geometric lattice (simple matroid) are logarithmically concave. We show this conjecture to be equivalent to proving an upper bound on the number of new copoints…

Combinatorics · Mathematics 2011-11-10 W. M. B. Dukes

We relate two conjectures that play a central role in the reported proof of Rota's Conjecture. Let $\mathbb F$ be a finite field. The first conjecture states that: the branch-width of any $\mathbb F$-representable $N$-fragile matroid is…

Combinatorics · Mathematics 2019-09-09 Jim Geelen , Florian Hoersch

We show that, for points along the moment curve, the bar-and-joint rigidity matroid and the hyperconnectivity matroid coincide, and that both coincide with the $C^{d-2}_{d-1}$-cofactor rigidity of points along any (non-degenerate) conic in…

Combinatorics · Mathematics 2023-03-16 Luis Crespo Ruiz , Francisco Santos

We prove that the linear matroid that defines generic rigidity of $d$-dimensional body-rod-bar frameworks (i.e., structures consisting of disjoint bodies and rods mutually linked by bars) can be obtained from the union of ${d+1 \choose 2}$…

Combinatorics · Mathematics 2012-04-26 Shin-ichi Tanigawa

For which values of $k$ does a uniformly chosen $3$-regular graph $G$ on $n$ vertices typically contain $ n/k$ vertex-disjoint $k$-cycles (a $k$-cycle factor)? To date, this has been answered for $k=n$ and for $k \ll \log n$; the former,…

Combinatorics · Mathematics 2014-04-21 Jeff Kahn , Eyal Lubetzky , Nicholas Wormald

The problem of covering the ground set of two matroids by a minimum number of common independent sets is notoriously hard even in very restricted settings, i.e.\ when the goal is to decide if two common independent sets suffice or not.…

Combinatorics · Mathematics 2023-02-06 Kristóf Bérczi , Tamás Schwarcz

We show that the basis graph of an even delta-matroid is Hamiltonian if it has more than two vertices. More strongly, we prove that for two distinct edges $e$ and $f$ sharing a common end, it has a Hamiltonian cycle using $e$ and avoiding…

Combinatorics · Mathematics 2025-08-15 Donggyu Kim , Sang-il Oum

We consider the equilibrium equations for a conducting elastic rod placed in a uniform magnetic field, motivated by the problem of electrodynamic space tethers. When expressed in body coordinates the equations are found to sit in a…

Mathematical Physics · Physics 2010-07-06 D. Sinden , G. H. M. van der Heijden

A set of vertices of a graph is said to be in general position if no three vertices from the set lie on a common geodesic. Recently Klav\v{z}ar, Rall and Yero generalized this notion by defining a set of vertices to be in general…

Combinatorics · Mathematics 2024-09-10 Brent Cody , Garrett Moore

We establish several Witten type rigidity and vanishing theorems for twisted Toeplitz operators on odd dimensional manifolds. We obtain our results by combining the modular method, modular transgression and some careful analysis of odd…

Differential Geometry · Mathematics 2015-04-24 Fei Han , Jianqing Yu

Vassiliev (finite type) invariants of knots can be described in terms of weight systems. These are functions on chord diagrams satisfying so-called 4-term relations. In the study of the sl2 weight system, it was shown that its value on a…

Combinatorics · Mathematics 2016-02-02 Sergey Lando , Vyacheslav Zhukov

We introduce a parametrization of the coupling constant space of the generalized Kontsevich models in terms of a set of moments equivalent to those introduced recently in the context of topological gravity. For the simplest generalization…

High Energy Physics - Theory · Physics 2009-10-28 C. Kristjansen

We give axiomatic foundations for non-finitary infinite matroids with duality, in terms of independent sets, bases, circuits, closure and rank. This completes the solution to a problem of Rado of 1966.

Combinatorics · Mathematics 2013-02-26 Henning Bruhn , Reinhard Diestel , Matthias Kriesell , Rudi Pendavingh , Paul Wollan

Halin proved that every minimally $k$-connected graph has a vertex of degree $k$. More generally, does every minimally vertically $k$-connected matroid have a $k$-element cocircuit? Results of Murty and Wong give an affirmative answer when…

Combinatorics · Mathematics 2022-05-27 James Oxley , Zach Walsh

Firstly, we wish to motivate that Conley pairs, realized via Salamon's definition [17], are rather useful building blocks in geometry: Initially we met Conley pairs in an attempt to construct Morse filtrations of free loop spaces [21]. From…

Dynamical Systems · Mathematics 2020-05-25 Joa Weber

We study a counting version of Cycle Double Cover Conjecture. We discuss why it is more interesting to count circuits (i.e., graphs isomorphic to $C_k$ for some $k$) instead of cycles (graphs with all degrees even). We give an…

Combinatorics · Mathematics 2024-09-12 Radek Hušek , Robert Šámal

In 1959, Erd\H{o}s and Gallai proved that every graph G with average vertex degree ad(G)\geq 2 contains a cycle of length at least ad(G). We provide an algorithm that for k\geq 0 in time 2^{O(k)} n^{O(1)} decides whether a 2-connected…

Data Structures and Algorithms · Computer Science 2022-02-08 Fedor V. Fomin , Petr A. Golovach , Danil Sagunov , Kirill Simonov

In this paper we research a model of multilayer circuits with a single logical layer. We consider $\lambda$-separable graphs as a support for circuits. We establish the Shannon function lower bound $\max \bigl(\frac{2^n}{n}, \frac{2^n (1 -…

Computational Complexity · Computer Science 2021-03-16 T. R. Sitdikov , G. V. Kalachev