supported by NSFC(No.11171273);sponsored by the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University(No.22016170)
Supported by the National Natural Science Foundation of China(11171273); Supported by the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical Uni- versity(Z2016170)
A k-cyclic graph is a connected graph of order n and size n + k-1. In this paper, we determine the maximal signless Laplacian spectral radius and the corresponding extremal graph among all C_4-free k-cyclic graphs of ...
Supported by the National Natural Science Foundation of China(Grant No.11171273);the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University(Grant No.Z2016170)
The Q-index of a graph G is the largest eigenvalue q(G) of its signless Laplacian matrix Q(G). In this paper, we prove that the wheel graph W_n = K_1 ∨C_(n-1)is the unique graph with maximal Q-index among all H...