Results 11 to 20 of about 29,610 (306)
ON DISTANCE–REGULAR GRAPHS OF DIAMETER 3 WITH EIGENVALUE \(\theta=1\)
Ural Mathematical Journal, 2022 For a distance-regular graph \(\Gamma\) of diameter 3, the graph \(\Gamma_i\) can be strongly regular for \(i=2\) or 3. J.Kulen and co-authors found the parameters of a strongly regular graph \(\Gamma_2\) given the intersection array of the graph ...
Alexander A. Makhnev +2 more
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Transitive distance-regular graphs from linear groups $L(3,q)$, $q = 2,3,4,5$ [PDF]
Transactions on Combinatorics, 2020 In this paper we classify distance-regular graphs, including strongly regular graphs, admitting a transitive action of the linear groups $L(3,2)$, $L(3,3)$, $L(3,4)$ and $L(3,5)$ for which the rank of the permutation representation is at most 15.
Andrea Svob
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Spreads in strongly regular graphs [PDF]
Designs Codes and Cryptography, 1996 A spread in any geometry is a set of pairwise disjoint lines that cover all the points. For a partial geometry the point graph (collinearity graph) is strongly regular. Delsarte showed that a clique in a strongly regular graph has at most \(K = 1 - k/s\) vertices, where \(k\) and \(s\) are the largest and smallest eigenvalues of the graph respectively.
Haemers, W.H., Touchev, V.D.
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Approximately strongly regular graphs
Discrete Mathematics, 2023 We give variants of the Krein bound and the absolute bound for graphs with a spectrum similar to that of a strongly regular graph. In particular, we investigate what we call approximately strongly regular graphs. We apply our results to extremal problems. Among other things, we show the following: (1) Caps in $\mathrm{PG}(n, q)$ for which the number of
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Strongly Regular Graphs Having Strongly Regular Subconstituents
Journal of Algebra, 1978 No abstract.
Cameron, P.J. +2 more
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Certain Concepts in Vague Graph with an Application
Discrete Dynamics in Nature and Society, 2022 Vague graphs (VGs), belonging to the FGs family, have good capabilities when faced with problems that cannot be expressed by FGs. When an element’s membership is not clear, neutrality is a good option that can be well-supported by a VG.
Xiaolong Shi +3 more
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Graph isomorphism and Gaussian boson sampling
Special Matrices, 2021 We introduce a connection between a near-term quantum computing device, specifically a Gaussian boson sampler, and the graph isomorphism problem. We propose a scheme where graphs are encoded into quantum states of light, whose properties are then probed ...
Brádler Kamil +4 more
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Observations on the Lovász θ-Function, Graph Capacity, Eigenvalues, and Strong Products
Entropy, 2023 This paper provides new observations on the Lovász θ-function of graphs. These include a simple closed-form expression of that function for all strongly regular graphs, together with upper and lower bounds on that function for all regular graphs.
Igal Sason
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Transitive $t$-designs and strongly regular graphs constructed from linear groups $L(2,q)$, $q leq 23$ [PDF]
International Journal of Group Theory, 2019 In this paper we construct transitive $t$-designs from the linear groups $L(2,q), q leq 23$. Thereby we classify $t$-designs, $t ge 2$, admitting a transitive action of the linear groups $L(2,q), q leq 23$, up to 35 points and obtained ...
Dean Crnković, Andrea Švob
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A unique and novel graph matrix for efficient extraction of structural information of networks
Electronic Journal of Graph Theory and Applications, 2021 In this article, we propose a new type of square matrix associated with an undirected graph by trading off the natural embedded symmetry in them. The proposed matrix is defined using the neighbourhood sets of the vertices, called as neighbourhood matrix
Sivakumar Karunakaran +1 more
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