Results 41 to 50 of about 355 (50)
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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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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Orientable ℤN-Distance Magic Graphs
Discussiones Mathematicae Graph Theory, 2019 Let G = (V, E) be a graph of order n. A distance magic labeling of G is a bijection ℓ: V → {1, 2, . . ., n} for which there exists a positive integer k such that ∑x∈N(v)ℓ(x) = k for all v ∈ V, where N(v) is the open neighborhood of v.
Cichacz Sylwia +2 more
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EURO Journal on Computational Optimization, 2017 One challenge for social network researchers is to evaluate balance in a social network. The degree of balance in a social group can be used as a tool to study whether and how this group evolves to a possible balanced state.
Mario Levorato +3 more
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Skew-signings of positive weighted digraphs
Arab Journal of Mathematical Sciences, 2018 An arc-weighted digraph is a pair (D , ω) where D is a digraph and ω is an arc-weight function that assigns to each arc u v of D a nonzero real number ω (u v) .
Kawtar Attas +2 more
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Signed graphs with strong (anti-)reciprocal eigenvalue property
Special MatricesA (signed) graph is said to exhibit the strong reciprocal (anti-reciprocal) eigenvalue property (SR) (resp., (-SR)) if for any eigenvalue λ\lambda , it has 1λ\frac{1}{\lambda } (resp.,−1λ-\frac{1}{\lambda }) as an eigenvalue as well, with the same ...
Belardo Francesco, Huntington Callum
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Characterization of Line-Consistent Signed Graphs
, 2015 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 signed graphs, i.e.
Slilaty, Daniel C., Zaslavsky, Thomas
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Small-span Hermitian matrices over quadratic integer rings
, 2013 Building on the classification of all characteristic polynomials of integer symmetric matrices having small span (span less than 4), we obtain a classification of small-span polynomials that are the characteristic polynomial of a Hermitian matrix over ...
Greaves, Gary
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Eigenvalues of complex unit gain graphs and gain regularity
Special MatricesA complex unit gain graph (or T{\mathbb{T}}-gain graph) Γ=(G,γ)\Gamma =\left(G,\gamma ) is a gain graph with gains in T{\mathbb{T}}, the multiplicative group of complex units.
Brunetti Maurizio
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On the weights of simple paths in weighted complete graphs
, 2012 Consider a weighted graph G with n vertices, numbered by the set {1,...,n}. For any path p in G, we call w_G(p) the sum of the weights of the edges of the path and we define the multiset {\cal D}_{i,j} (G) = {w_G(p) | p simple path between i and j} We ...
Rubei, Elena
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