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Related papers: A signed graph product and its Application

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In this paper, we look into Signed Product Cordial Labeling for Splitting Graphs of Bull graph and Splitting graph of Star graph , Square of Path graph, Coronaand also for the graph obtained by joining two copies of Helm by a Path of…

Combinatorics · Mathematics 2025-11-11 S. Soundar Rajan , J. Baskar Babujee

A graph is strongly perfect if every induced subgraph H has a stable set that meets every nonempty maximal clique of H. The characterization of strongly perfect graphs by a set of forbidden induced subgraphs is not known. Here we provide…

Combinatorics · Mathematics 2020-03-05 Maria Chudnovsky , Cemil Dibek , Paul Seymour

A signed circuit is a minimal signed graph (with respect to inclusion) that admits a nowhere-zero flow. We show that each flow-admissible signed graph on $m$ edges can be covered by signed circuits of total length at most $(3+2/3)\cdot m$,…

Combinatorics · Mathematics 2017-06-14 Tomáš Kaiser , Robert Lukot'ka , Edita Máčajová , Edita Rollová

Graph Laplacian learning, also known as network topology inference, is a problem of great interest to multiple communities. In Gaussian graphical models (GM), graph learning amounts to endowing covariance selection with the Laplacian…

Machine Learning · Computer Science 2024-02-14 Changhao Shi , Gal Mishne

A signed graph is a graph whose edges are labeled positive or negative. The sign of a cycle is the product of the signs of its edges. Zaslavsky proved in 2012 that, up to switching isomorphism, there are six different signed Petersen…

Combinatorics · Mathematics 2021-10-12 Deepak Sehrawat , Bikash Bhattacharjya

A signed graph is a pair $(G,\tau)$ of a graph $G$ and its sign $\tau$, where a \textit{sign} $\tau$ is a function from $\{ (e,v)\mid e\in E(G),v\in V(G), v\in e\}$ to $\{1,-1\}$. Note that graphs or digraphs are special cases of signed…

Combinatorics · Mathematics 2020-04-03 JiSun Huh , Sangwook Kim , Boram Park

A unified approach to the determination of eigenvalues and eigenvectors of specific matrices associated with directed graphs is presented. Matrices studied include the distance matrix, distance Laplacian, and distance signless Laplacian, in…

Combinatorics · Mathematics 2020-08-04 Minerva Catral , Lorenzo Ciardo , Leslie Hogben , Carolyn Reinhart

Let us consider a compact oriented riemannian manifold M without boundary and of dimension n=4k. The signature of M is defined as the signature of a given quadratic form Q. Two different products could be used to define Q and they render…

Differential Geometry · Mathematics 2015-06-02 Jose Rodriguez

A complex unit hypergraph is a hypergraph where each vertex-edge incidence is given a complex unit label. We define the adjacency, incidence, Kirchoff Laplacian and normalized Laplacian of a complex unit hypergraph and study each of them.…

Combinatorics · Mathematics 2024-05-17 Raffaella Mulas , Nathan Reff

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

Subgraph reconfiguration is a family of problems focusing on the reachability of the solution space in which feasible solutions are subgraphs, represented either as sets of vertices or sets of edges, satisfying a prescribed graph structure…

Data Structures and Algorithms · Computer Science 2018-03-19 Tesshu Hanaka , Takehiro Ito , Haruka Mizuta , Benjamin Moore , Naomi Nishimura , Vijay Subramanya , Akira Suzuki , Krishna Vaidyanathan

Let $G$ be a simple graph. The signless Laplacian spread of $G$ is defined as the maximum distance of pairs of its signless Laplacian eigenvalues. This paper establishes some new bounds, both lower and upper, for the signless Laplacian…

Spectral Theory · Mathematics 2018-05-31 Enide Andrade , Geir Dahl , Laura Leal , María Robbiano

In this article, we develop a perturbative technique to construct families of non-isomorphic discrete graphs which are isospectral for the standard (also called normalised) Laplacian and its signless version. We use vertex contractions as a…

Combinatorics · Mathematics 2022-07-11 Fernando Lledó , John S. Fabila-Carrasco , Olaf Post

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

In this paper, we present two new matrices, namely the resistance Laplacian and resistance signless Laplacian matrix of a connected graph. We provide a generalized form of these matrices for different classes of graphs, including the…

Combinatorics · Mathematics 2024-01-30 Shivani Tushar Parab , Raisa DSouza

An oriented hypergraph is an oriented incidence structure that generalizes and unifies graph and hypergraph theoretic results by examining its locally signed graphic substructure. In this paper we obtain a combinatorial characterization of…

Combinatorics · Mathematics 2020-09-29 Gina Chen , Vivian Liu , Ellen Robinson , Lucas J. Rusnak , Kyle Wang

For any given graph G = (V,E) we define in a certain way a new graph G(x,y,z) with the vertex set V\cup E depending on parameters x,y,z from {0,1, +, -} and call graph G(x,y,z) the (x,y,z)-transformation of G. It turns out that if G is an…

Combinatorics · Mathematics 2017-05-16 Aiping Deng , Alexander Kelmans , Juan Meng

A signed graph is a graph in which every edge carries a $+$ or a $-$ sign. In this paper, we determine the signed graphs with maximum spectral radius among all unbalanced signed graphs with fixed order that contain neither negative…

Combinatorics · Mathematics 2024-07-24 Yiting Cai , Bo Zhou

We investigate string graphs through the lens of graph product structure theory, which describes complicated graphs as subgraphs of strong products of simpler building blocks. A graph $G$ is called a string graph if its vertices can be…

Combinatorics · Mathematics 2025-11-20 Nikolai Karol

A graph $G$ is factored into graphs $H$ and $K$ via a matrix product if there exist adjacency matrices $A$, $B$, and $C$ of $G$, $H$, and $K$, respectively, such that $A = BC$. In this paper, we study the spectral aspects of the matrix…

Combinatorics · Mathematics 2024-07-08 Saieed Akbari , Yi-Zheng Fan , Fu-Tao Hu , Babak Miraftab , Yi Wang