REMARK ON ORDINARY AND RANDIC ENERGY OF GRAPHS

Let G be an undirected simple graph with n vertices and m edges. Denote with vertical bar lambda(1)vertical bar >=vertical bar lambda(2)vertical bar >=center dot center dot center dot >=vertical bar lambda(n)vertical bar and vertical bar rho(1)vertical bar >=vertical bar rho(2)vertical bar >=center dot center dot center dot >=vertical bar rho(n)vertical bar absolute eigenvalues and Randle eigenvalues of G arranged in non -increasing order, respectively. Upper bound of graph invariant E(G) = Sigma(n)(i=1) vertical bar lambda(i)vertical bar, and lower and upper bounds of invariant RE (G) = Sigma(n)(i=1) vertical bar rho(i)vertical bar are obtained in this paper.