ON THE NULLITY OF CONNECTED GRAPHS WITH LEAST EIGENVALUE AT LEAST-2

被引:6
作者
Zhou, Jiang [1 ]
Sun, Lizhu [1 ]
Yao, Hongmei [1 ]
Bu, Changjiang [1 ]
机构
[1] Harbin Engn Univ, Coll Sci, Harbin 150001, Peoples R China
关键词
Nullity; generalized line graph; adjacency matrix; signless Laplacian matrix; LINE GRAPHS; MAXIMUM NULLITY; STARLIKE TREES;
D O I
10.2298/AADM130710014Z
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
Let L (resp. L+) be the set of connected graphs with least adjacency eigenvalue at least -2 (resp. larger than -2). The nullity of a graph G, denoted by eta(G), is the multiplicity of zero as an eigenvalue of the adjacency matrix of G. In this paper, we give the nullity set of L+ and an upper bound on the nullity of exceptional graphs. An expression for the nullity of generalized line graphs is given. For G is an element of L, if eta(G) is sufficiently large, then G is a proper generalized line graph (G is not a line graph).
引用
收藏
页码:250 / 261
页数:12
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