Results 41 to 50 of about 122 (75)
Existence and Classification of 3‐Regular Symmetric Graphs of Order 6pq With Distinct Primes p and q
Journal of Mathematics, Volume 2025, Issue 1, 2025.A graph Σ is said symmetric if its automorphism group acts transitively on the set of its arc. Let p < q be two distinct prime integers. This paper demonstrates that connected 3‐regular symmetric graphs of order 6pq exist if and only if the pair (p, q) belongs to the set (5, 19), (19, 37), (37, 73), which up to isomorphism there are nine sporadic ones,
Mehdi Alaeiyan +3 more
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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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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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The Planar Index and Outerplanar Index of Some Graphs Associated to Commutative Rings
Discussiones Mathematicae - General Algebra and Applications, 2019 In this paper, we study the planar and outerplanar indices of some graphs associated to a commutative ring. We give a full characterization of these graphs with respect to their planar and outerplanar indices when R is a finite ring.
Barati Zahra, Afkhami Mojgan
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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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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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