Results 21 to 30 of about 37,702 (263)
On Singular Signed Graphs with Nullspace Spanned by a Full Vector: Signed Nut Graphs
Discussiones Mathematicae Graph Theory, 2022 A signed graph has edge weights drawn from the set {+1, −1}, and is sign-balanced if it is equivalent to an unsigned graph under the operation of sign switching; otherwise it is sign-unbalanced.
Bašić Nino +3 more
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Homomorphisms of planar signed graphs to signed projective cubes [PDF]
Discrete Mathematics & Theoretical Computer Science, 2013 We conjecture that every signed graph of unbalanced girth 2g, whose underlying graph is bipartite and planar, admits a homomorphism to the signed projective cube of dimension 2g1.
Reza Naserasr +2 more
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Degree of an edge and Platt Number in signed networks
Ratio Mathematica, 2023 Positive labelled edges play a vital role in network analysis.The degree of edges in signed graphs is introduced by giving importance to positive edges incident on the end vertices of that edge. The concept of Platt number of a graph, which is the sum of
Diviya K D, Anjaly Kishore
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COMMON-EDGE SIGNED GRAPH OF A SIGNED GRAPH [PDF]
Journal of the Indonesian Mathematical Society, 2010 A Smarandachely k-signed graph (Smarandachely k-marked graph) is anordered pair....DOI : http://dx.doi.org/10.22342/jims.16.2.34.105 ...
P. Siva Kota Reddy +2 more
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Discrete Applied Mathematics, 1982 AbstractA signed graph is a graph with a sign attached to each arc. This article introduces the matroids of signed graphs, which generalize both the polygon matroids and the even-circle (or unoriented cycle) matroids of ordinary graphs. The concepts of balance, switching, restriction and contraction, double covering graphs, and linear representation of
Ghorbani, Ebrahim +3 more
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A study on integer additive set-valuations of signed graphs
Karpatsʹkì Matematičnì Publìkacìï, 2015 Let $\mathbb{N}_0$ denote the set of all non-negative integers and $\mathcal{P}(\mathbb{N}_0)$ be its power set. An integer additive set-labeling (IASL) of a graph $G$ is an injective set-valued function $f:V(G)\to\mathcal{P}(\mathbb{N}_0)\setminus ...
N.K. Sudev, K.A. Germina
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Edge coloring signed graphs [PDF]
Discrete Mathematics, 2020 We define a method for edge coloring signed graphs and what it means for such a coloring to be proper. Our method has many desirable properties: it specializes to the usual notion of edge coloring when the signed graph is all-negative, it has a natural definition in terms of vertex coloring of a line graph, and the minimum number of colors required for
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Signed distance Laplacian matrices for signed graphs
Linear and Multilinear Algebra, 2022 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 graphs using these matrices and find signed distance laplacian spectra of some classes of unbalanced signed graphs.
Roshni T. Roy +3 more
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Weak signed Roman domination in graphs [PDF]
Communications in Combinatorics and Optimization, 2020 A weak signed Roman dominating function (WSRDF) of a graph $G$ with vertex set $V(G)$ is defined as a function $f:V(G)\rightarrow\{-1,1,2\}$ having the property that $\sum_{x\in N[v]}f(x)\ge 1$ for each $v\in V(G)$, where $N[v]$ is the closed ...
Lutz Volkmann
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Chromatic Polynomials of Signed Book Graphs
Theory and Applications of Graphs, 2022 For $m \geq 3$ and $n \geq 1$, the $m$-cycle \textit{book graph} $B(m,n)$ consists of $n$ copies of the cycle $C_m$ with one common edge. In this paper, we prove that (a) the number of switching non-isomorphic signed $B(m,n)$ is $n+1$, and (b) the ...
Deepak Sehrawat, Bikash Bhattacharjya
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