On two conjectures on sum of the powers of signless Laplacian   eigenvalues of a graph
  Let $G$ be a simple graph and $Q(G)$ be the signless Laplacian matrix of $G$. Let $S_\alpha(G)$ be the sum of the $\alpha$-th powers of the nonzero eigenvalues of $Q(G)$. We disprove two conjectures by You and Yang on the extremal values of $S_\alpha(G)$ among bipartite graphs and among graphs with bounded connectivity. 
F. Ashraf
math.CO