Unicyclic graphs with exactly two main eigenvalues

An eigenvalue of a graph G is called a main eigenvalue if it has an eigenvector the sum of whose entries is not equal to zero, and it is well known that a graph has exactly one main eigenvalue if and only if it is regular. In this work, all connected unicyclic graphs with exactly two main eigenvalues are determined. c 2006 Elsevier Ltd. All rights reserved.

• Type: Journal
• Year: 2006
• Where: APPML
• Authors: Yaoping Hou, Feng Tian
• Keywords: APPML 2006, Eigenvalues, Eigenvector, Main Eigenvalues