English
Related papers

Related papers: Signed degree sets in signed graphs

200 papers

A weighted graph $G^{\omega}$ consists of a simple graph $G$ with a weight $\omega$, which is a mapping,$\omega$: $E(G)\rightarrow\mathbb{Z}\backslash\{0\}$. A signed graph is a graph whose edges are labeled with $-1$ or $1$. In this paper,…

Combinatorics · Mathematics 2017-08-24 S. Akbari , A. Ghafari , K. Kazemian , M. Nahvi

A signed graph is a graph $G$ associated with a mapping $\sigma: E(G)\to \{-1,+1\}$, denoted by $(G,\sigma)$. A $cycle$ of $(G,\sigma)$ is a connected 2-regular subgraph. A cycle $C$ is $positive$ if it has an even number of negative edges,…

Combinatorics · Mathematics 2018-03-09 Yezhou Wu , Dong Ye

This note gives necessary and sufficient conditions for a sequence of non-negative integers to be the degree sequence of a connected simple graph. This result is implicit in a paper of Hakimi. A new alternative characterisation of these…

Combinatorics · Mathematics 2015-12-01 Jonathan McLaughlin

A signed graph is a pair $(G,\Sigma)$, where $G=(V,E)$ is a graph (in which parallel edges are permitted, but loops are not) with $V={1,...,n}$ and $\Sigma\subseteq E$. By $S(G,\Sigma)$ we denote the set of all symmetric $V\times V$…

Combinatorics · Mathematics 2012-08-28 Marina Arav , Frank J. Hall , Zhongshan Li , Hein van der Holst

A signed graph $ (G, \Sigma)$ is a graph positive and negative ($\Sigma $ denotes the set of negative edges). To re-sign a vertex $v$ of a signed graph $ (G, \Sigma)$ is to switch the signs of the edges incident to $v$. If one can obtain $…

Combinatorics · Mathematics 2016-04-01 Sandip Das , Soumen Nandi , Soumyajit Paul , Sagnik Sen

A graph $G$ of order $2n$ is called degree-equipartite if for every $n$-element set $A\subseteq V(G)$, the degree sequences of the induced subgraphs $G[A]$ and $G[V(G)\setminus A]$ are the same. In this paper, we characterize all…

Combinatorics · Mathematics 2011-08-09 Khodakhast Bibak , Mohammad Hassan Shirdareh Haghighi

A signed graph is a graph in which each edge has a positive or negative sign. In this article, first we characterize the distance compatibility in the case of a connected signed graph and discussed the distance compatibility criterion for…

Combinatorics · Mathematics 2020-09-21 T. V. Shijin , P. Soorya , K. Shahul Hameed , K. A. Germina

A signed graph $\Sigma$ is a pair $(G,\sigma)$, where $G=(V,E)$ is the underlying graph in which each edge is assigned $+1$ or $-1$ by the signature function $\sigma:E\rightarrow\{-1,+1\}$. In this paper, we extend the extensively applied…

Combinatorics · Mathematics 2021-06-24 Shahul Hameed K , Remna K P , Divya T2 , Biju K , Rajeevan P , Santhosh G O2 , Ramakrishnan K O

Necessary and sufficient conditions for a sequence of positive integers to be the degree sequence of a k-connected simple graph are detailed. Conditions are also given under which such a sequence is necessarily k-connected.

Combinatorics · Mathematics 2015-12-19 Jonathan McLaughlin

In this paper, we study the net-regular strongly regular signed graphs with degree 6 and determine all connected 6-regular and net-regular strongly regular signed graphs. There are three, six and four 6-regular strongly regular signed…

Combinatorics · Mathematics 2025-08-04 Qian Yu , Yaoping Hou

A signed graph is a pair $(G,\Sigma)$, where $G=(V,E)$ is a graph (in which parallel edges are permitted, but loops are not) with $V=\{1,...,n\}$ and $\Sigma\subseteq E$. The edges in $\Sigma$ are called odd and the other edges even. By…

Combinatorics · Mathematics 2012-09-21 Marina Arav , Frank J. Hall , Zhongshan Li , Hein van der Holst

In a signed graph each edge has a sign, $+1$ or $-1$. We introduce in the present paper a new definition of connection in a signed graph by the existence of both positive and negative chains between vertices. We prove some results and…

Combinatorics · Mathematics 2017-08-08 Ouahiba Bessouf , Abdelkader Khelladi , Thomas Zaslavsky

Let $G$ be a graph. For a given positive integer $d$, let $f_G(d)$ denote the largest integer $t$ such that in every coloring of the edges of $G$ with two colors there is a monochromatic subgraph with minimum degree at least $d$ and order…

Combinatorics · Mathematics 2007-05-23 Yair Caro , Raphael Yuster

Signed graphs are graphs with signed edges. They are commonly used to represent positive and negative relationships in social networks. While balance theory and clusterizable graphs deal with signed graphs to represent social interactions,…

Discrete Mathematics · Computer Science 2014-05-21 Anne-Marie Kermarrec , Christopher Thraves

Given a set $\mathcal{F}$ of graphs, a graph $G$ is $\mathcal{F}$-free if $G$ does not contain any member of $\mathcal{F}$ as an induced subgraph. Barrus, Kumbhat, and Hartke [M. D. Barrus, M. Kumbhat, and S. G. Hartke, Graph classes…

Combinatorics · Mathematics 2015-08-04 Michael D. Barrus , Stephen G. Hartke

There are many concepts of signed graph coloring which are defined by assigning colors to the vertices of the graphs. These concepts usually differ in the number of self-inverse colors used. We introduce a unifying concept for this kind of…

Combinatorics · Mathematics 2022-11-07 Chiara Cappello , Eckhard Steffen

Let G be a simple graph without isolated vertices. For a vertex i in G, the degree d_i is the number of vertices adjacent to i and the average 2-degree m_i is the mean of the degrees of the vertices which are adjacent to i. The sequence of…

Combinatorics · Mathematics 2018-11-08 Yu-pei Huang , Chia-an Liu , Chih-wen Weng

Necessary and sufficient conditions for a sequence of positive integers to be the degree sequence of a 3-connected simple graph are detailed. Conditions are also given under which such a sequence is necessarily 3-connected i.e. the sequence…

Combinatorics · Mathematics 2015-12-18 Jonathan McLaughlin

A signed graph is one that features two types of edges: positive and negative. Balanced signed graphs are those in which all cycles contain an even number of positive edges. In the adjacency matrix of a signed graph, entries can be $0$,…

Combinatorics · Mathematics 2024-08-15 Cristian M. Conde , Ezequiel Dratman , Luciano N. Grippo

A signed graph is a graph whose edges are labeled either positive or negative. Corresponding to the two signed distance matrices defined for signed graphs, we define two signed distance laplacian matrices. We characterize balance in signed…

Combinatorics · Mathematics 2020-10-12 Roshni T Roy , K A Germina , K Shahul Hameed , Thomas Zaslavsky