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In~\cite{rotvandervorst} a homology theory --Morse-Conley-Floer homology-- for isolated invariant sets of arbitrary flows on finite dimensional manifolds is developed. In this paper we investigate functoriality and duality of this homology…

Dynamical Systems · Mathematics 2015-02-04 T. O. Rot , R. C. A. M. Vandervorst

We define notions of local topological convergence and local geometric convergence for embedded graphs in $\mathbb{R}^n,$ and study their properties. The former is related to Benjamini-Schramm convergence, and the latter to weak convergence…

Probability · Mathematics 2017-06-28 Benjamin Schweinhart

This article is concerned with Kronecker flows on the infinite torus. The work is partly motivated by the fact that many Hamiltonian PDEs and systems on infinite lattices admit invariant tori, of possibly infinite dimension, on which the…

Dynamical Systems · Mathematics 2026-04-03 Lorenzo Baroni

In communication networks, the binding numbers of graphs (or networks) are often used to measure the vulnerability and robustness of graphs (or networks). Furthermore, the fractional factors of graphs and the fractional…

Combinatorics · Mathematics 2023-06-22 Sizhong Zhou

In this sequence of two papers, we introduce a curvature flow on (mixed) weighted graphs which is based on the Bakry-\'Emery calculus. The flow is described via a time-continuous evolution through the weighting schemes. By adapting this…

Classical Analysis and ODEs · Mathematics 2022-12-27 David Cushing , Supanat Kamtue , Shiping Liu , Florentin Münch , Norbert Peyerimhoff , Hugo Benedict Snodgrass

This is a graduate-level introduction to graph theory, corresponding to a quarter-long course. It covers simple graphs, multigraphs as well as their directed analogues, and more restrictive classes such as tournaments, trees and…

History and Overview · Mathematics 2025-06-10 Darij Grinberg

We study transport processes on infinite metric graphs with non-constant velocities and matrix boundary conditions in the $\\mathrm{L}^{\infty}$-setting. We apply the theory of bi-continuous operator semigroups to obtain well-posedness of…

Analysis of PDEs · Mathematics 2021-05-20 Christian Budde , Marjeta Kramar Fijavž

The Jacobian of a graph is a discrete analogue of the Jacobian of a Riemann surface. In this paper, we explore how Jacobians of graphs change when we glue two graphs along a common subgraph focusing on the case of cycle graphs. Then, we…

Combinatorics · Mathematics 2023-08-16 Alessandro Chilelli , Jaiung Jun

An account of 2-factors in graphs and their history is presented. We give a direct graph-theoretic proof of the 2-Factor Theorem and a new variant of it, and also a new complete characterisation of the maximal graphs without 2-factors. This…

Combinatorics · Mathematics 2026-05-08 Jan van den Heuvel , Bjarne Toft

We present the theory of multifunctions applied to graphs. Its interesting feature is that walks are recognized as iterations. We consider the graphs with arbitrary number of vertices which are determined by multifunctions. The mutually…

General Mathematics · Mathematics 2017-11-02 Artur Gizycki

We introduce and study a multivariate function that counts nowhere-zero flows on a graph G, in which each edge of G has an individual capacity. We prove that the associated counting function is a piecewise-defined polynomial in these…

Combinatorics · Mathematics 2016-05-10 Matthias Beck , Alyssa Cuyjet , Gordon Rojas Kirby , Molly Stubblefield , Michael Young

Flow cones of a directed acyclic graph admit a family of unimodular triangulations given by Danilov, Karzanov, and Koshevoy (DKK) whose normal fans are related to (generalizations) of the associahedron and permutahedron. A correspondence…

Combinatorics · Mathematics 2026-03-17 Antoine Abram , Jose Bastidas , Benjamin Dequêne , Alejandro H. Morales , GaYee Park , Hugh Thomas

We give a generating function for the number of graphs with given numerical properties and prescribed weighted number of connected components. As an application, we give a generating function for the number of bipartite graphs of given…

Combinatorics · Mathematics 2016-06-28 Joungmin Song

A system of 'telegrapher's' equations for a number of long lines joined into a network is studied. Explicit formulas for Fourier transforms of current and voltage are derived. These formulas are very suitable for computer application as…

Classical Physics · Physics 2009-02-24 Nikolai Dokuchaev

Let $r \geq 2$ be a real number. A complex nowhere-zero $r$-flow on a graph $G$ is an orientation of $G$ together with an assignment $\varphi\colon E(G)\to \mathbb{C}$ such that, for all $e \in E(G)$, the modulus of the complex number…

Combinatorics · Mathematics 2023-03-21 Davide Mattiolo , Giuseppe Mazzuoccolo , Jozef Rajník , Gloria Tabarelli

We show that, under some technical conditions, the Strong Slope Conjecture proposed by Kalfagianni and Tran is closed under connect sums and cabling. As an application, we establish the Strong Slope Conjecture for graph knots.

Geometric Topology · Mathematics 2019-12-24 Kenneth L Baker , Kimihiko Motegi , Toshie Takata

A graph is almost bipartite if it contains exactly one odd cycle, and it is Konig-Egervary if the sum of the independence number and the matching number equals the order of the graph. We introduce the class of Bipartite-Almost Bipartite…

Combinatorics · Mathematics 2026-03-12 Kevin Pereyra

We provide a new perspective on the divisor theory of graphs, using additive combinatorics. As a test case for this perspective, we compute the gonality of certain families of outerplanar graphs, specifically the strip graphs. The Jacobians…

Combinatorics · Mathematics 2024-08-20 David Jensen , Doel Rivera Laboy

In 1972 Tutte famously conjectured that every 4-edge-connected graph has a nowhere zero 3-flow; this is known to be equivalent to every 5-regular, 4-edge-connected graph having an edge orientation in which every in-degree is either 1 or 4.…

Combinatorics · Mathematics 2025-04-18 Michelle Delcourt , Reaz Huq , Pawel Pralat

We study a two-parameter family of one-dimensional maps and related (a,b)-continued fractions suggested for consideration by Don Zagier. We prove that the associated natural extension maps have attractors with finite rectangular structure…

Dynamical Systems · Mathematics 2010-04-26 Svetlana Katok , Ilie Ugarcovici