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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.
Willem H. Haemers, Vladimir D. Tonchev
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On strongly regular graphs with m2 = qm3 and m3 = qm2 for q = 7/2, 7/3, 7/4, 7/5, 7/6 [PDF]
Yugoslav Journal of Operations Research, 2021 We say that a regular graph G of order n and degree r ≥ 1 (which is not the complete graph) is strongly regular if there exist non-negative integers τ and θ such that |Si ∩ Sj| = τ for any two adjacent vertices i and j, and |Si ∩ Sj| = θ for any
Lepović Mirko
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The application domain of difference type matrix D(r,0,s,0,t) on some sequence spaces [PDF]
Yugoslav Journal of Operations Research, 2021 We say that a regular graph G of order n and degree r ≥ 1 (which is not the complete graph) is strongly regular if there exist non-negative integers τ and θ such that |Si ∩ Sj | = τ for any two adjacent vertices i and j, and |Si ∩ Sj | = θ for any two ...
Paul Avinoy, Tripathy Binod Chandra
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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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On r-Edge Regular Neutrosophic Graphs [PDF]
Neutrosophic Sets and Systems, 2023 We approach learning characteristic on a neutrosophic graph such as r-edge regular neutrosophic graph, strongly edge regular neutrosophic graph and absolute degree of vertex since a neutrosophic set 𝑁𝑆 = {〈𝑥, 𝑁𝑆𝔗(𝑥), 𝑁𝑆𝔩 (𝑥), 𝑁𝑆𝔉(𝑥)〉; 𝑥 ∈ 𝑋} of a ...
M. Kaviyarasu
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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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An upper bound for difference of energies of a graph and its complement
Examples and Counterexamples, 2023 The A-energy of a graph G, denoted by EA(G), is defined as sum of the absolute values of eigenvalues of adjacency matrix of G. Nikiforov in Nikiforov (2016) proved that EA(G¯)−EA(G)≤2μ¯1and EA(G)−EA(G¯)≤2μ1for any graph G and posed a problem to find best
Harishchandra S. Ramane +2 more
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On the Integrability of Strongly Regular Graphs [PDF]
Graphs and Combinatorics, 2019 Koolen et al. showed that if a connected graph with smallest eigenvalue at least $-3$ has large minimal valency, then it is $2$-integrable. In this paper, we will prove that a lower bound for the minimal valency is 166.
Jack H. Koolen +2 more
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Extension of Strongly Regular Graphs [PDF]
The Electronic Journal of Combinatorics, 2008 The Friendship Theorem states that if any two people in a party have exactly one common friend, then there exists a politician who is a friend of everybody. In this paper, we generalize the Friendship Theorem. Let $\lambda$ be any nonnegative integer and $\mu$ be any positive integer.
Gera, Ralucca, Shen, J.
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Examples and Counterexamples, 2023 A new strongly regular graph with parameters (81,30,9,12) is found as a graph invariant under certain subgroup of the full automorphism group of the previously known strongly regular graph discovered in 1981 by J. H. van Lint and A. Schrijver.
Dean Crnković, Andrea Švob
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