Results 1 to 10 of about 31,404 (294)
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 Haemers +2 more
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5-chromatic strongly regular graphs [PDF]
Discrete Mathematics, 2006 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Willem Haemers
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Applications of Strongly Regular Cayley Graphs to Codebooks
IEEE Access, 2023 In this paper, we give a construction of strongly regular Cayley graphs on the finite field $\mathbb {F}_{q^{n}}$ . As applications of these strongly regular Cayley graphs, a class of codebooks is presented and proved to be asymptotically optimal with ...
Qiuyan Wang +3 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 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
G R Omidi, E R Van Dam
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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 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 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
openaire +3 more sources