Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8897771 | Linear Algebra and its Applications | 2018 | 12 Pages |
Abstract
Let G be a k-connected irregular graph with n vertices, m edges, maximum degree Î and minimum degree δ. In this paper, we mainly show2Îâq1(G)>2(nÎâ2m)k22(nÎâ2m)[(nâ2+2kâÎ)(nâδâ1)+k2]+nk2, where q1(G) is the signless Laplacian spectral radius of G. The inequality improves previous bounds of several authors in some cases. It also implies a lower bound of 2Îâq1(H) for a proper subgraph H of a k-connected Î-regular graph. Another lower bound of 2Îâq1(G) for a connected graph G is also given.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Wenjie Ning, Mei Lu, Kun Wang, Daqing Jiang,