Abstract
Abstract For G being a graph with n vertices and m edges, and with Laplacian eigenvalues μ1≥μ2≥⋯≥μn-1≥μn=0, the Laplacian energy is defined as LE=Σi=1n|μi-2m/n|. Let σ be the largest positive integer such that μσ ≥ 2m/n. We characterize the graphs satisfying σ=n-1. Using this, we obtain lower bounds for LE in terms of n, m, and the first Zagreb index. In addition, we present some upper bounds for LE in terms of graph invariants such as n, m, maximum degree, vertex cover number, and spanning tree packing number.
| Original language | English |
|---|---|
| Article number | 21335 |
| Pages (from-to) | 83-92 |
| Number of pages | 10 |
| Journal | Applied Mathematics and Computation |
| Volume | 268 |
| DOIs | |
| State | Published - 11 Jul 2015 |
Keywords
- Edge connectivity
- Laplacian eigenvalues
- Laplacian energy
- Spanning tree packing number
- Vertex connectivity
- Vertex cover number