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Trudy Instituta Matematiki i Mekhaniki UrO RAN, 2008, Volume 14, Number 3, Pages 127–131
(Mi timm46)
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Amply regular graphs with Hoffman's condition
V. V. Kabanov, S. V. Unegov Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences
Abstract:
It is known that, if the minimal eigenvalue of a graph is $-2$, then the graph satisfies Hoffman's condition: for any generated complete bipartite subgraph $K_{1,3}$ (a 3-claw) with parts $\{p\}$ and $\{q_1, q_2,q_3\}$, any vertex distinct from $p$ and adjacent to the vertices $q_1$ and $q_2$ is adjacent to $p$ but not adjacent to $q_3$. We prove the converse statement for amply regular graphs containing a 3-claw and satisfying the condition $\mu>1$.
Received: 09.09.2008
Citation:
V. V. Kabanov, S. V. Unegov, “Amply regular graphs with Hoffman's condition”, Trudy Inst. Mat. i Mekh. UrO RAN, 14, no. 1, 2008, 127–131; Proc. Steklov Inst. Math. (Suppl.), 264, suppl. 1 (2009), S150–S154
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Abstract page: | 329 | Full-text PDF : | 87 | References: | 58 |
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