English
Related papers

Related papers: Connectivity versus Lin-Lu-Yau curvature

200 papers

A graph on at least ${{k+1}}$ vertices is uniformly $k$-connected if each pair of its vertices is connected by $k$ and not more than $k$ independent paths. We reinvestigate a recent constructive characterization of uniformly $3$-connected…

Combinatorics · Mathematics 2024-08-07 Frank Göring , Tobias Hofmann

In this paper we compare the combinatorial Ricci curvature on cell complexes and the LLY-Ricci curvature defined on graphs. A cell complex is correspondence to a graph such that the vertexes are cells and the edges are vectors on the cell…

Combinatorics · Mathematics 2018-09-28 Kazuyoshi Watanabe , Taiki Yamada

In this paper we consider the following problem: Over the class of all simple connected graphs of order $n$ with $k$ pendant vertices ($n,k$ being fixed), which graph maximizes (respectively, minimizes) the algebraic connectivity? We also…

Combinatorics · Mathematics 2010-03-25 Arbind K. Lal , Kamal L. Patra , Binod K. Sahoo

In this paper, we show that the edge connectivity of a distance-regular digraph $\Gamma$ with valency $k$ is $k$ and for $k>2$, any minimum edge cut of $\Gamma$ is the set of all edges going into (or coming out of) a single vertex. Moreover…

Combinatorics · Mathematics 2017-02-07 S. Ashkboos , G. R. Omidi , F. Shafiei , K. Tajbakhsh

In this paper, we present some new results describing connections between the spectrum of a regular graph and its generalized connectivity, toughness, and the existence of spanning trees with bounded degree.

Combinatorics · Mathematics 2016-02-19 Sebastian M. Cioabă , Xiaofeng Gu

The main paradigm of smoothed analysis on graphs suggests that for any large graph $G$ in a certain class of graphs, perturbing slightly the edges of $G$ at random (usually adding few random edges to $G$) typically results in a graph having…

Combinatorics · Mathematics 2015-08-13 Michael Krivelevich , Daniel Reichman , Wojciech Samotij

Liu, M\"unch, and Peyerimhoff introduced the notion of Bakry-\'Emery curvature for connection graphs as a means to derive Buser-type bounds on the eigenvalues of connection Laplacians. In this work, we present a reformulation of the…

Combinatorics · Mathematics 2026-04-08 Chunyang Hu , Shiping Liu

The paper defines a positive semidefinite operator called $\epsilon-$repelling Laplacian on a positive connected signed graph where $\epsilon$ is an arbitrary positive number less than a constant $\epsilon_0$ related to the graph's…

Spectral Theory · Mathematics 2026-04-14 Yong Lin , Shi Wan

The $\ell$-component connectivity (or $\ell$-connectivity for short) of a graph $G$, denoted by $\kappa_\ell(G)$, is the minimum number of vertices whose removal from $G$ results in a disconnected graph with at least $\ell$ components or a…

Discrete Mathematics · Computer Science 2021-05-25 Jou-Ming Chang , Kung-Jui Pai , Ro-Yu Wu , Jinn-Shyong Yang

The edge-fault-tolerance of networks is of great significance to the design and maintenance of networks. For any pair of vertices $u$ and $v$ of the connected graph $G$, if they are connected by $\min \{ \deg_G(u),\deg_G(v)\}$ edge-disjoint…

Combinatorics · Mathematics 2022-09-27 Dong Liu. Pingshan Li , Bicheng Zhang

A labelled, undirected graph is a graph whose edges have assigned labels, from a specific set. Given a labelled, undirected graph, the well-known minimum labelling spanning tree problem is aimed at finding the spanning tree of the graph…

Discrete Mathematics · Computer Science 2018-07-03 Jose' Andres Moreno Perez , Sergio Consoli

Increasing the connectivity of a graph is a pivotal challenge in robust network design. The weighted connectivity augmentation problem is a common version of the problem that takes link costs into consideration. The problem is then to find…

Data Structures and Algorithms · Computer Science 2024-02-13 Marcelo Fonseca Faraj , Ernestine Großmann , Felix Joos , Thomas Möller , Christian Schulz

Based on earlier work by Carlen-Maas and the second- and third-named author, we introduce the notion of intertwining curvature lower bounds for graphs and quantum Markov semigroups. This curvature notion is stronger than both Bakry-\'Emery…

Functional Analysis · Mathematics 2024-01-11 Florentin Münch , Melchior Wirth , Haonan Zhang

We introduce the concept of matching connectivity as a notion of connectivity in graph admitting perfect matchings which heavily relies on the structural properties of those matchings. We generalise a result of Robertson, Seymour and Thomas…

Combinatorics · Mathematics 2019-02-25 Archontia C. Giannopoulou , Stephan Kreutzer , Sebastian Wiederrecht

Hasunuma [J. Graph Theory 102 (2023) 423-435] conjectured that for any tree $T$ of order $m$, every $k$-connected (or $k$-edge-connected) graph $G$ with minimum degree at least $k+m-1$ contains a tree $T'\cong T$ such that $G-E(T')$ is…

Combinatorics · Mathematics 2023-03-08 Qing Yang , Yingzhi Tian

Let $G$ be a connected graph. The average distance of a vertex $v$ of $G$ is the arithmetic mean of the distances from $v$ to all other vertices of $G$. The proximity and remoteness of $G$ are defined as the minimum and maximum,…

Combinatorics · Mathematics 2025-08-15 Peter Dankelmann , Sonwabile Mafunda , Sufiyan Mallu

Let $G$ be a graph with adjacency matrix $A(G)$ and let $D(G)$ be the diagonal matrix of vertex degrees of $G$. For any real $\alpha \in [0,1]$, Nikiforov defined the $A_\alpha$-matrix of a graph $G$ as $A_\alpha(G)=\alpha…

Combinatorics · Mathematics 2023-06-14 Jiayu Lou , Ligong Wang , Ming Yuan

The general sum-connectivity index of a graph $G$ is defined as $\chi_\alpha(G)=\sum\limits_{uv\in E(G)} {(d(u)+d(v))^{\alpha}}$, where $d(v)$ denotes the degree of the vertex $v$ in $G$ and $\alpha$ is a real number. In this paper it is…

Combinatorics · Mathematics 2018-07-13 M. K. Jamil , I. Tomescu

A k-tree is either a complete graph on (k+1) vertices or given a k-tree G' with n vertices, a k-tree G with (n+1) vertices can be constructed by introducing a new vertex v and picking a k-clique Q in G' and then joining each vertex u in Q.…

Discrete Mathematics · Computer Science 2011-03-25 Suresh Badarla , R Rama

A good edge-labelling of a simple, finite graph is a labelling of its edges with real numbers such that, for every ordered pair of vertices (u,v), there is at most one nondecreasing path from u to v. In this paper we prove that any graph on…

Combinatorics · Mathematics 2014-03-18 Abbas Mehrabian , Dieter Mitsche , Paweł Prałat