F. Ashraf

collaborators

2 papers

math.CO2014

On two conjectures on sum of the powers of signless Laplacian eigenvalues of a graph

F. Ashraf

Let $G$ be a simple graph and $Q (G)$ be the signless Laplacian matrix of $G$ . Let $S_{α} (G)$ be the sum of the $α$ -th powers of the nonzero eigenvalues of $Q (G)$ . We disprove two con…

math.CO2014

Nordhaus--Gaddum type inequalities for Laplacian and signless Laplacian eigenvalues

F. Ashraf, B. Tayfeh-Rezaie

Let $G$ be a graph with $n$ vertices. We denote the largest signless Laplacian eigenvalue of $G$ by $q_{1} (G)$ and Laplacian eigenvalues of $G$ by $μ_1(G)\ge\cdots\geμ_{n-1}(G)\geμ_n…