首页|A Note on the Signless Laplacian Spectral Ordering of Graphs with Given Size

A Note on the Signless Laplacian Spectral Ordering of Graphs with Given Size

扫码查看
For a simple undirected graph G with fixed size m ≥ 2k(k ∈ Z+)and maximum degree Δ(G)≤ m-k,we give an upper bound on the signless Laplacian spectral radius q(G)of G.For two connected graphs G1 and G2 with size m ≥ 8,employing this upper bound,we prove that q(G1)>q(G2)if Δ(G1)>Δ(G2)+1 and Δ(G1)≥ m/2+2.For triangle-free graphs,we prove two stronger results.As an application,we completely characterize the graph with maximal signless Laplacian spectral radius among all graphs with size m and circumference c for m ≥ max{2c,c+9},which partially answers the question proposed by Chen et al.in[Linear Algebra Appl.,2022,645:123-136].

signless Laplacian spectral radiusupper boundorderingsizecircumference

Nannan LIU、Shuguang GUO

展开 >

School of Mathematics and Statistics,Qinghai Normal University,Qinghai 810008,P.R.China

School of Mathematics and Statistics,Yancheng Teachers University,Jiangsu 224002,P.R.China

National Natural Science Foundation of ChinaNational Natural Science Foundation of China

1207141112171222

2024

数学研究及应用
大连理工大学

数学研究及应用

影响因子:0.094
ISSN:2095-2651
年,卷(期):2024.44(3)
  • 30