The signless Laplacian spectral radius of graphs without trees

Ming-Zhu Chen, Zhao-Ming Li, Xiao-Dong Zhang

Let $Q(G)=D(G)+A(G)$ be the signless Laplacian matrix of a simple graph of order $n$, where $D(G)$ and $A(G)$ are the degree diagonal matrix and the adjacency matrix of $G$, respec…