A note on the second largest eigenvalue of a tree with perfect matchings

摘要

In this paper, we present an upper bound for the second largest eigenvalue of a tree on n = 2k = 4t (t greater than or equal to 2) vertices with perfect matchings. At the same time, the few largest second largest eigenvalues over the class of trees on n = 2k = 4t (t greater than or equal to 2) vertices with perfect matchings are also obtained. (C) 2003 Elsevier Inc. All rights reserved. [References: 6]