An inequality for regular near polygons

dc.creatorTerwilliger, Paul
dc.creatorWeng, Chih-wen
dc.date2003-12-07
dc.date.accessioned2026-07-07T05:03:38Z
dc.date.available2026-07-07T05:03:38Z
dc.descriptionLet $G$ denote a near-polygon distance-regular graph with diameter $d\geq 3$, valency $k$ and intersection numbers $a_1>0$, $c_2>1$. Let $θ_1$ denote the second largest eigenvalue for the adjacency matrix of $G$. We show $θ_1$ is at most $(k-a_1-c_2)/(c_2-1)$. We show the following are equivalent: (i) Equality is attained above; (ii) $G$ is $Q$-polynomial with respect to $θ_1$; (iii) $G$ is a dual polar graph or a Hamming graph.
dc.description13 pages
dc.identifierhttps://arxiv.org/abs/math/0312149
dc.identifierhttp://arxiv.org/abs/math/0312149
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/69501
dc.subjectCombinatorics
dc.subject05E30
dc.titleAn inequality for regular near polygons
dc.typetext

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