Results 11 to 20 of about 329,714 (296)
The H-Line Signed Graph Of A Signed Graph [PDF]
viXra, 2010 For standard terminology and notion in graph theory we refer the reader to Harary; the non-standard will be given in this paper as and when required. We treat only finite simple graphs without self loops and isolates.
R. Rangarajan +2 more
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Tutte’s dichromate for signed graphs [PDF]
Discrete Applied Mathematics, 2021 We introduce the ``trivariate Tutte polynomial" of a signed graph as an invariant of signed graphs up to vertex switching that contains among its evaluations the number of proper colorings and the number of nowhere-zero flows. In this, it parallels the Tutte polynomial of a graph, which contains the chromatic polynomial and flow polynomial as ...
Goodall, A. +3 more
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Further Results on the Nullity of Signed Graphs [PDF]
Journal of Applied Mathematics, 2014 The nullity of a graph is the multiplicity of the eigenvalue zero in its spectrum. A signed graph is a graph with a sign attached to each of its edges. In this paper, we apply the coefficient theorem on the characteristic polynomial of a signed graph and
Yu Liu, Lihua You
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Characterization of Line-Consistent Signed Graphs
Discussiones Mathematicae Graph Theory, 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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Signed degree sets in signed graphs [PDF]
, 2006 The set D of distinct signed degrees of the vertices in a signed graph G is called its signed degree set. In this paper, we prove that every non-empty set of positive (negative) integers is the signed degree set of some connected signed graph and ...
S. Pirzada +2 more
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On signed degrees in signed graphs [PDF]
Czechoslovak Mathematical Journal, 1994 A graph is called signed if there is a designation of its edges as either positive or negative. The signed degree of a vertex \(v\) is the number of positive edges through \(v\) less the number of negative edges through \(v\). The degree sequence consists of signed degrees of all vertices in nonincreasing order.
Gary Chartrand +3 more
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On sign-symmetric signed graphs
Ars Mathematica Contemporanea, 2020 A signed graph is said to be sign-symmetric if it is switching isomorphic to its negation. Bipartite signed graphs are trivially sign-symmetric. We give new constructions of non-bipartite sign-symmetric signed graphs. Sign-symmetric signed graphs have a symmetric spectrum but not the other way around.
Hamid Reza Maimani +3 more
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Ars Mathematica Contemporanea, 2022 The total graph is built by joining the graph to its line graph by means of the incidences. We introduce a similar construction for signed graphs. Under two similar definitions of the line signed graph, we define the corresponding total signed graph and we show that it is stable under switching.
Belardo F., Stanic Z., Zaslavsky T.
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Negative (and positive) circles in signed graphs: A problem collection
AKCE International Journal of Graphs and Combinatorics, 2018 A signed graph is a graph whose edges are labeled positive or negative. The sign of a circle (cycle, circuit) is the product of the signs of its edges. Most of the essential properties of a signed graph depend on the signs of its circles. Here I describe
Thomas Zaslavsky
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Laplacian integral signed graphs with few cycles
AIMS Mathematics, 2023 A connected graph with n vertices and m edges is called k-cyclic graph if k=m−n+1. We call a signed graph is Laplacian integral if all eigenvalues of its Laplacian matrix are integers.
Dijian Wang, Dongdong Gao
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