A note on the second smallest eigenvalue of the normalized Laplacian of a graph

作者：Li, Hong-Hai^*; Su, Li

来源：Utilitas Mathematica, 2015, 98: 171-181.

• normalized Laplacian
• second smallest eigenvalue
• eigenvalue bounds
• harmonic eigenfunction

Let G be a simple graph and L be its normalized Laplacian. Let lambda(n-1) be the second smallest eigenvalue of L. We first give a characterization of the graphs with lambda(n-1). Moreover, we present a lower bound on lambda(n-1), which is much better than Chung's and Grossman's bounds in some sense. Finally, we give a formal proof of Lovasz's bound on lambda(n-1).

• 出版日期2015-11
• 单位江西师范大学