Let $\cal M$ be a class of strongly regular graphs for which $\mu$ is a nonprincipal eigenvalue. Note that the neighborhood of any vertex of an $AT4$-graph lies in $\cal M$. Previously, the parameters of graphs from $\cal M$ were described. In this paper, intersection arrays of $AT4$-graphs with $q\le 4$ and the parameters of the corresponding strongly regular graphs are found.
Keywords: strongly regular graph, $AT4$-graph, locally $\cal M$-graph
Received August 16, 2024
Revised October 15, 2024
Accepted October 21, 2024
Dmitrii Viktorovich Paduchikh, Dr. Phys.-Math. Sci., Prof., Krasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences, Yekaterinburg, 620108 Russia, e-mail: dpaduchikh@gmail.com
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Cite this article as: D.V. Paduchikh. Enumeration of intersection arrays of $AT4$-graphs with $q\le 4$. Trudy Instituta Matematiki i Mekhaniki UrO RAN, 2024, vol. 30, no. 4, pp. 207–211.
