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We examine the conditions under which a signed graph contains an edge or a vertex that is contained in a unique negative circle or a unique positive circle. For an edge in a unique signed circle, the positive and negative case require the…

Combinatorics · Mathematics 2017-01-03 Richard Behr

The line graph of a graph with signed edges carries vertex signs. A vertex-signed graph is consistent if every circle (cycle, circuit) has positive vertex-sign product. Acharya, Acharya, and Sinha recently characterized line-consistent…

Combinatorics · Mathematics 2021-06-21 Daniel C. Slilaty , Thomas Zaslavsky

A signed graph $(G,\sigma)$ is a graph $G$ with a signature $\sigma$ labeling each edge with a positive or negative sign. Two signatures of $G$ are switching equivalent if one is obtained from the other by changing the signs of all edges in…

Combinatorics · Mathematics 2026-03-13 Zhiqian Wang

A signed graph $(G,\sigma)$ is a graph $G$ together with an assignment $\sigma$ of either a positive sign or a negative sign to each edge. A signed graph is unbalanced if it contains a cycle with odd number of negative edges. The spectral…

Combinatorics · Mathematics 2026-04-17 Yiting Cai , Hongying Lin , Bo Zhou

The set D of distinct signed degrees of the vertices in a signed graph G is called its signed degree set. In this paper, we prove that every non-empty set of positive (negative) integers is the signed degree set of some connected signed…

Combinatorics · Mathematics 2007-05-23 S. Pirzada , T. A. Naikoo , F. A. Dar

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 signed graph is a simple graph with two types of edges: positive and negative edges. Switching a vertex $v$ of a signed graph corresponds to changing the type of each edge incident to $v$. A homomorphism from a signed graph $G$ to another…

Combinatorics · Mathematics 2021-05-13 Fabien Jacques , Alexandre Pinlou

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

Signed graphs have their edges labeled either as positive or negative. Here we introduce two types of signed distance matrix for signed graphs. We characterize balance in signed graphs using these matrices and we obtain explicit formulae…

Combinatorics · Mathematics 2021-06-21 Shahul Hameed K , Shijin T , Soorya P , Germina K A , Thomas Zaslavsky

A signed graph $\Gamma$ is said to be determined by its spectrum if every signed graph with the same spectrum as $\Gamma$ is switching isomorphic with $\Gamma$. Here it is proved that the path $P_n$, interpreted as a signed graph, is…

Combinatorics · Mathematics 2018-05-11 Saieed Akbari , Willem H. Haemers , Hamid Reza Maimani , Leila Parsaei Majd

A signed graph is a pair $(G,\sigma)$, where $G$ is a graph and $\sigma: E(G)\rightarrow \{-, +\}$, called signature, is an assignment of signs to the edges. Given a signed graph $(G,\sigma)$ with no negative loops, a balanced…

Combinatorics · Mathematics 2025-04-18 Xiaolan Hu , Luis Kuffner , Jiaao Li , Reza Naserasr , Lujia Wang , Zhouningxin Wang , Xiaowei Yu

A signed graph is a graph whose edges are labeled either as positive or negative. The concept of vector valued switching and balancing dimension of signed graphs were introduced by S. Hameed et al. In this paper, we deal with the balancing…

Combinatorics · Mathematics 2023-06-21 Albin Mathew , Germina K. A

An edge uv in a graph \Gamma\ is directionally 2-signed (or, (2,d)-signed) by an ordered pair (a,b), a,b in {+,-}, if the label l(uv) = (a,b) from u to v, and l(vu) = (b,a) from v to u. Directionally 2-signed graphs are equivalent to…

Combinatorics · Mathematics 2016-10-18 E. Sampathkumar , M. A. Sriraj , Thomas Zaslavsky

A signed graph is a graph with edges marked positive and negative; it is unbalanced if some cycle has negative sign product. We introduce the concept of vector valued switching function in signed graphs, which extends the concept of…

Combinatorics · Mathematics 2023-05-23 Shahul Hameed K , Albin Mathew , Germina K A , Thomas Zaslavsky

Let $G$ be a graph and $A$ be its adjacency matrix. A graph $G$ is invertible if its adjacency matrix $A$ is invertible and the inverse of $G$ is a weighted graph with adjacency matrix $A^{-1}$. A signed graph $(G,\sigma)$ is a weighted…

Combinatorics · Mathematics 2023-03-23 Isaiah Osborne , Dong Ye

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

A signed graph $G$ is a graph where each edge is assigned a + (positive edge) or a - (negative edge). The signed degree of a vertex $v$ in a signed graph, denoted by $sdeg(v)$, is the number of positive edges incident to $v$ subtracted by…

Combinatorics · Mathematics 2021-09-06 Alvaro Carbonero , Janelle Domantay , Karen Guthrie

In a graph $G$, a vertex dominates itself and its neighbors. A subset $D \subseteq V(G)$ is a double dominating set of $G$ if $D$ dominates every vertex of $G$ at least twice. A signed graph $\Sigma = (G,\sigma)$ is a graph $G$ together…

Combinatorics · Mathematics 2022-06-20 Deepak Sehrawat , Bikash Bhattacharjya

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 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