A note on triangle-free distance-regular graphs with a2 ≠ 0

被引：5
|
作者：
Pan, Yeh-jong [1 ]
Weng, Chih-wen [1 ]
机构：
[1] Natl Chiao Tung Univ, Dept Appl Math, Hsinchu 300, Taiwan
来源：
JOURNAL OF COMBINATORIAL THEORY SERIES B | 2009年 / 99卷 / 01期
关键词：
Distance-regular graphs; Classical parameters; CLOSED SUBGRAPHS;
D O I：
10.1016/j.jctb.2008.07.005
中图分类号：
O1 [数学];
学科分类号：
0701 ; 070101 ;
摘要：
Let Gamma denote a distance-regular graph with classical parameters (D, b, alpha, beta) and D >= 3. Assume the intersection numbers a(1) = 0 and a(2) not equal 0. We show that the intersection number c(2) is either 1 or 2, and if c(2) = 1, then (b, alpha, beta) = (-2, -2, ((-2)(D+l) - 1)/3). (C) 2008 Elsevier Inc. All rights reserved.
引用
收藏
页码：266 / 270
页数：5
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