A NOTE ON SOME LOWER BOUNDS OF THE LAPLACIAN ENERGY OF A GRAPH

For a simple connected graph G of order n and size m, the Laplacian energy of G is dened as LE(G) = Σn i=1 ji - 2m n j where 1; 2; : : : ; n-1; n are the Laplacian eigenvalues of G satisfying 1 2 n-1 > n = 0. In this note, some new lower bounds on the graph invariant LE(G) are derived. The obtained results are compared with some already known lower bounds of LE(G).