Results 1 to 10 of about 29,931 (112)
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 +2 more
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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
Ferdinand Ihringer
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Homomorphisms of Strongly Regular Graphs [PDF]
Electronic Notes in Discrete Mathematics, 2016 We prove that if G and H are primitive strongly regular graphs with the same parameters and φ
David E Robérson
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Strongly walk-regular graphs [PDF]
Journal of Combinatorial Theory - Series A, 2013 We study a generalization of strongly regular graphs. We call a graph strongly walk-regular if there is an $\ell >1$ such that the number of walks of length $\ell$ from a vertex to another vertex depends only on whether the two vertices are the same, adjacent, or not adjacent. We will show that a strongly walk-regular graph must be an empty graph, a
Edwin R Van Dam, G R Omidi
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5-chromatic strongly regular graphs [PDF]
Discrete Mathematics, 2006 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Willem H Haemers
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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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Hamiltonian Strongly Regular Graphs [PDF]
SSRN Electronic Journal, 2008 We give a sufficient condition for a distance-regular graph to be Hamiltonian. In particular, the Petersen graph is the only connected non-Hamiltonian strongly regular graph on fewer than 99 vertices.
Brouwer, A.E., Haemers, W.H.
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Cyclotomy and Strongly Regular Graphs [PDF]
Journal of Algebraic Combinatorics, 1999 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Brouwer, A. E. +2 more
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On the Complexity of Identifying Strongly Regular Graphs [PDF]
Australas. J Comb., 2022 New result- GI is not AC0-reducible to isomorphism testing of conference graphs; fixed minor bugs and typos from previous ...
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