Results 31 to 40 of about 318 (45)

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, Freyberg Bryan, Froncek Dalibor   +2 more
doaj   +1 more source

Evaluating balancing on social networks through the efficient solution of correlation clustering problems

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, Rosa Figueiredo, Yuri Frota, Lúcia Drummond   +3 more
doaj   +1 more source

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, Abderrahim Boussaïri, Mohamed Zaidi   +2 more
doaj   +1 more source

Signed graphs with strong (anti-)reciprocal eigenvalue property

Special Matrices
A (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
doaj   +1 more source

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
core   +2 more sources

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
core   +1 more source

Eigenvalues of complex unit gain graphs and gain regularity

Special Matrices
A 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
doaj   +1 more source

On the Potts model partition function in an external field

, 2012
We study the partition function of Potts model in an external (magnetic) field, and its connections with the zero-field Potts model partition function. Using a deletion-contraction formulation for the partition function Z for this model, we show that it ...
A.D. Sokal, A.D. Sokal, A.D. Sokal, B. Bollobás, B. Bollobás, B.A. Berg, C. Schulze, C.M. Fortuin, D. Andrén, D.J.A. Welsh, D.J.A. Welsh, E.H. Lieb, F.Y. Wu, F.Y. Wu, F.Y. Wu, G. Royle, G.E. Andrews, H. Meyer-Ortmanns, H.-O. Georgii, Iain Moffatt, J. Ellis-Monaghan, L. Beaudin, L. Traldi, L.A. Goldberg, Leslie M. McDonald, M. Aizenman, M. Biskup, N.B. Ouchi, R. Shrock, R.B. Potts, R.J. Baxter, S. Sanyal, S. Turner, S.C. Chang, S.C. Chang, S.D. Noble, T.C. Schelling, V. Jones, Y. Watanabe   +38 more
core   +2 more sources

Relations between connected and self-avoiding walks in a digraph [PDF]

, 2015
Walks in a directed graph can be given a partially ordered structure that extends to possibly unconnected objects, called hikes. Studying the incidence algebra on this poset reveals unsuspected relations between walks and self-avoiding hikes.
Espinasse, Thibault, Rochet, Paul
core   +3 more sources

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
core   +2 more sources