摘要
设B(n,α)是独立数为α的n阶双圈图,B_1(n,α)是由B(n,α)中含有两个边不交的圈构成的双圈图子集,B_2(n,α)=B(n,α)\B_1(n,α).文中分别研究了B_1(n,α)和B_2(n,α)中具有最大拟拉普拉斯谱半径的极图.进一步地,得到了B(n,α)中拟拉普拉斯谱半径的上界,并给出达到上界的极图.
Let B(n,α)be the class of bicyclic graphs on n vertices with independence numberα.Let B_1(n,α)be the subclass of B(n,α)consisting of all bicyclic graphs with two edge-disjoint cycles and B_2(n,α)=B(n,α)/B_1(n,α).This paper determined the unique graph with the maximal signless Laplacian spectral radius among all graphs in B_1(n,α) and B_2(n,α),respectively.Furthermore,the upper bound of the signless Laplacian spectral radius and the extremal graph for B(n,α)were also obtained.
出处
《华东师范大学学报(自然科学版)》
CAS
CSCD
北大核心
2011年第3期73-84,99,共13页
Journal of East China Normal University(Natural Science)
基金
国家自然科学基金(10771069)
关键词
拟拉普拉斯谱半径
双圈图
独立数
signless Laplacian spectral radius
bicyclic graph
independence number