Results 41 to 50 of about 122 (75)
Enumerating Problems Concerning Endomorphisms of Double Vertex Wheel Graphs
Journal of Mathematics, Volume 2024, Issue 1, 2024.We can define six classes of endomorphisms on a graph, and they always form a chain based on set inclusion. The concepts of endomorphism type and endomorphism spectrum were introduced by Böttcher and Knauer in 1992. They provided a systematic and organized approach to study endomorphisms of graphs.
Yu Li, Hailong Hou, Kaidi Xu, Huadong Su
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Note on the product of the largest and the smallest eigenvalue of a graph
Special MatricesIn this note, we use eigenvalue interlacing to derive an inequality between a graph’s maximum degree and its maximum and minimum adjacency eigenvalues. The equality case is fully characterized.
Abiad Aida +2 more
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Finite groups with star-free noncyclic graphs
Open Mathematics, 2019 For a finite noncyclic group G, let Cyc(G) be the set of elements a of G such that 〈a, b〉 is cyclic for each b of G. The noncyclic graph of G is a graph with the vertex set G ∖ Cyc(G), having an edge between two distinct vertices x and y if 〈x, y〉 is not
Ma Xuanlong, Walls Gary L., Wang Kaishun
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Journal of Mathematics, Volume 2024, Issue 1, 2024.Symmetry properties are of vital importance for graphs. The famous Cayley graph is a good mathematical model as its high symmetry. The normality of the graph can well reflect the symmetry of the graph. In this paper, we characterize the normality of the direct product of Cayley graphs and give a sufficient and necessary condition for the direct product
Li Wang +3 more
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End-regular and End-orthodox generalized lexicographic products of bipartite graphs
Open Mathematics, 2016 A graph X is said to be End-regular (End-orthodox) if its endomorphism monoid End(X) is a regular (orthodox) semigroup. In this paper, we determine the End-regular and the End-orthodox generalized lexicographic products of bipartite graphs.
Gu Rui, Hou Hailong
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On θ-commutators and the corresponding non-commuting graphs
Open Mathematics, 2017 The θ-commutators of elements of a group with respect to an automorphism are introduced and their properties are investigated. Also, corresponding to θ-commutators, we define the θ-non-commuting graphs of groups and study their correlations with other ...
Shalchi S., Erfanian A., Farrokhi DG M.
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Eccentric topological properties of a graph associated to a finite dimensional vector space
Main Group Metal Chemistry, 2020 A topological index is actually designed by transforming a chemical structure into a number. Topological index is a graph invariant which characterizes the topology of the graph and remains invariant under graph automorphism.
Liu Jia-Bao +5 more
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Cyclic Partitions of Complete and Almost Complete Uniform Hypergraphs
Discussiones Mathematicae Graph Theory, 2022 We consider cyclic partitions of the complete k-uniform hypergraph on a finite set V, minus a set of s edges, s ≥ 0. An s-almost t-complementary k-hypergraph is a k-uniform hypergraph with vertex set V and edge set E for which there exists a permutation ...
Dilbarjot, Gosselin Shonda Dueck
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On Perfectness of Intersection Graph of Ideals of ℤn
Discussiones Mathematicae - General Algebra and Applications, 2017 In this short paper, we characterize the positive integers n for which intersection graph of ideals of ℤn is perfect.
Das Angsuman
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Classifying cubic symmetric graphs of order 88p and 88p 2
Open MathematicsFor a simple graph Γ\Gamma , Γ\Gamma is said to be ss-regular, provided that the automorphism group of Γ\Gamma regularly acts on the set consisting of ss-arcs of Γ\Gamma .
Zhai Liangliang
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