English
Related papers

Related papers: Abrams's stable equivalence for graph braid groups

200 papers

We prove Farber's conjecture on the stable topological complexity of configuration spaces of graphs. The conjecture follows from a general lower bound derived from recent insights into the topological complexity of aspherical spaces. Our…

Algebraic Topology · Mathematics 2022-09-20 Ben Knudsen

Let $G$ be a graph of order $n$. A path decomposition $\mathcal{P}$ of $G$ is a collection of edge-disjoint paths that covers all the edges of $G$. Let $p(G)$ denote the minimum number of paths needed in a path decomposition of $G$. Gallai…

Combinatorics · Mathematics 2023-10-18 Xiaohong Chen , Baoyindureng Wu

Let $G$ be a graph of order $n$. A classical upper bound for the domination number of a graph $G$ having no isolated vertices is $\lfloor\frac{n}{2}\rfloor$. However, for several families of graphs, we have $\gamma(G) \le…

Combinatorics · Mathematics 2025-12-09 Subramanian Arumugam , Suresh Manjanath Hegde , Shashanka Kulamarva

We show that the groupoids of two directed graphs are isomorphic if and only if the two graphs are orbit equivalent by an orbit equivalence that preserves isolated eventually periodic points. We also give a complete description of the…

Dynamical Systems · Mathematics 2018-10-08 Toke Meier Carlsen , Marius Lie Winger

The minimal degree of a permutation group $G$ is the minimum number of points not fixed by non-identity elements of $G$. Lower bounds on the minimal degree have strong structural consequences on $G$. In 2014 Babai proved that the…

Combinatorics · Mathematics 2018-12-04 Bohdan Kivva

Discrete curvatures are quantities associated to the nodes and edges of a graph that reflect the local geometry around them. These curvatures have a rich mathematical theory and they have recently found success as a tool to analyze networks…

Physics and Society · Physics 2024-08-02 Michelle Roost , Karel Devriendt , Giulio Zucal , Jürgen Jost

A class of graphs is bridge-addable if given a graph $G$ in the class, any graph obtained by adding an edge between two connected components of $G$ is also in the class. The authors recently proved a conjecture of McDiarmid, Steger, and…

Combinatorics · Mathematics 2021-09-06 Guillaume Chapuy , Guillem Perarnau

The n-string braid group of a graph X is defined as the fundamental group of the n-point configuration space of the space X. This configuration space is a finite dimensional aspherical space. A. Abrams and R. Ghrist have conjectured that…

Geometric Topology · Mathematics 2007-05-23 Frank Connolly , Margaret Doig

The conjecture of Bollob\'as and Koml\'os, recently proved by B\"ottcher, Schacht, and Taraz [Math. Ann. 343(1), 175--205, 2009], implies that for any $\gamma>0$, every balanced bipartite graph on $2n$ vertices with bounded degree and…

Combinatorics · Mathematics 2011-07-28 Julia Böttcher , Peter Christian Heinig , Anusch Taraz

The Erd\H{o}s-Gallai Theorem states that every graph of average degree more than $l-2$ contains a path of order $l$ for $l\ge 2$. In this paper, we obtain a stability version of the Erd\H{o}s-Gallai Theorem in terms of minimum degree. Let…

Combinatorics · Mathematics 2019-08-05 Ming-Zhu Chen , Xiao-Dong Zhang

Much of extremal graph theory has concentrated either on finding very small subgraphs of a large graph (Turan-type results) or on finding spanning subgraphs (Dirac-type results). In this paper we are interested in finding intermediate-sized…

Combinatorics · Mathematics 2017-07-31 Peter Allen , Julia Böttcher , Jan Hladký

We prove that if g and n are integers at least two, then the abstract commensurator of the braid group with n strands on a closed orientable surface of genus g is naturally isomorphic to the extended mapping class group of a compact…

Group Theory · Mathematics 2015-02-02 Yoshikata Kida , Saeko Yamagata

Discrete Morse theory emerged as an essential tool for computational geometry and topology. Its core structures are discrete gradient fields, defined as acyclic matchings on a complex $C$, from which topological and geometrical informations…

Geometric Topology · Mathematics 2018-01-31 Joao Paixao , Joao Lagoas , Thomas Lewiner , Tiago Novello

We show that every cubic graph on $n$ vertices contains a spanning subgraph in which the number of vertices of each degree deviates from $\frac{n}{4}$ by at most $\frac{1}{2}$, up to three exceptions. This resolves the conjecture of Alon…

Combinatorics · Mathematics 2025-05-13 Borut Lužar , Jakub Przybyło , Roman Soták

We study the Ambrozio--Carlotto--Sharp (ACS) criterion on minimal isoparametric hypersurfaces $N^{n+1}\subset S^{n+2}$ with positive Ricci curvature, motivated by the Schoen--Marques--Neves conjecture on Morse index.For $g=4$ distinct…

Differential Geometry · Mathematics 2026-03-24 Niang Chen

We consider single-source shortest path algorithms that perform a sequence of relaxation steps whose ordering depends only on the input graph structure and not on its weights or the results of prior steps. Each step examines one edge of the…

Data Structures and Algorithms · Computer Science 2023-05-17 David Eppstein

Graphons $W$ can be used as stochastic models to sample graphs $G_n$ on $n$ nodes for $n$ arbitrarily large. A graphon $W$ is said to have the $H$-property if $G_n$ admits a decomposition into disjoint cycles with probability one as $n$…

Optimization and Control · Mathematics 2021-11-12 Mohamed-Ali Belabbas , Xudong Chen , Tamer Basar

Let ${\rm dim}(G)$ and $D(G)$ respectively denote the metric dimension and the distinguishing number of a graph $G$. It is proved that $D(G) \le {\rm dim}(G)+1$ holds for every connected graph $G$. Among trees, exactly paths and stars…

Combinatorics · Mathematics 2025-07-08 Meysam Korivand , Nasrin Soltankhah , Sandi Klavžar

Robin Forman's highly influential 2002 paper A User's Guide to Discrete Morse Theory presents an overview of the subject in a very readable manner. As a proof of concept, the author determines the topology (homotopy type) of the abstract…

Combinatorics · Mathematics 2025-01-20 Anupam Mondal , Pritam Chandra Pramanik

We say a graph $G$ has a Hamiltonian path if it has a path containing all vertices of $G$. For a graph $G$, let $\sigma_2(G)$ denote the minimum degree sum of two nonadjacent vertices of $G$; restrictions on $\sigma_2(G)$ are known as…

Combinatorics · Mathematics 2020-01-07 Ilkyoo Choi , Jinha Kim