Results 21 to 30 of about 318 (45)
On graphlike k-dissimilarity vectors [PDF]
, 2013 Let {\cal G}=(G,w) be a positive-weighted simple finite graph, that is, let G be a simple finite graph endowed with a function w from the set of the edges of G to the set of the positive real numbers.
Baldisserri, Agnese, Rubei, Elena
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Inertias of Laplacian matrices of weighted signed graphs
Special Matrices, 2019 We study the sets of inertias achieved by Laplacian matrices of weighted signed graphs. First we characterize signed graphs with a unique Laplacian inertia.
Monfared K. Hassani +3 more
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Total Minimal Dominating Signed Graph [PDF]
, 2010 Cartwright and Harary considered graphs in which vertices represent persons and the edges represent symmetric dyadic relations amongst persons each of which designated as being positive or negative according to whether the nature of the relationship is ...
Reddy, Siva Kota, Vijay, S.
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Trees with Unique Least Central Subtrees
Discussiones Mathematicae Graph Theory, 2018 A subtree S of a tree T is a central subtree of T if S has the minimum eccentricity in the join-semilattice of all subtrees of T. Among all subtrees lying in the join-semilattice center, the subtree with minimal size is called the least central subtree ...
Kang Liying, Shan Erfang
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Further results on the nullity of signed graphs [PDF]
, 2013 The nullity of a graph is the multiplicity of the eigenvalues zero in its spectrum. A signed graph is a graph with a sign attached to each of its edges.
Liu, Yu, You, Lhua
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Signed Complete Graphs with Maximum Index
Discussiones Mathematicae Graph Theory, 2020 Let Γ = (G, σ) be a signed graph, where G is the underlying simple graph and σ E(G) → {−, +} is the sign function on the edges of G. The adjacency matrix of a signed graph has −1 or +1 for adjacent vertices, depending on the sign of the edges.
Akbari Saieed +3 more
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On Regular Signed Graphs with Three Eigenvalues
Discussiones Mathematicae Graph Theory, 2020 In this paper our focus is on regular signed graphs with exactly 3 (distinct) eigenvalues. We establish certain basic results; for example, we show that they are walk-regular.
Anđelić Milica +2 more
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A note on the eigenvalue free intervals of some classes of signed threshold graphs
Special Matrices, 2019 We consider a particular class of signed threshold graphs and their eigenvalues. If Ġ is such a threshold graph and Q(Ġ ) is a quotient matrix that arises from the equitable partition of Ġ , then we use a sequence of elementary matrix operations to prove
Anđelić Milica +2 more
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Balancedness and the Least Laplacian Eigenvalue of Some Complex Unit Gain Graphs
Discussiones Mathematicae Graph Theory, 2020 Let 𝕋4 = {±1, ±i} be the subgroup of 4-th roots of unity inside 𝕋, the multiplicative group of complex units. A complex unit gain graph Φ is a simple graph Γ = (V (Γ) = {v1, . . .
Belardo Francesco +2 more
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Eigenpairs of adjacency matrices of balanced signed graphs
Special MatricesIn this article, we study eigenvalues λ\lambda and their associated eigenvectors xx of the adjacency matrices AA of balanced signed graphs. Balanced signed graphs were first introduced and studied by Harary to handle a problem in social psychology ...
Chen Mei-Qin
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