4 papers
math.CO2024
Maximizing the signless Laplacian spectral radius of some theta graphs
Yuxiang Liu, Ligong Wang
Let be the signless Laplacian matrix of a simple graph , where and are the degree diagonal matrix and the adjacency matrix of , respectively. T…
math.CO2024
Extension on spectral extrema of gem-free graph with given size
Yuxiang Liu, Ligong Wang
A graph is -free if does not contain as a subgraph. Let denote the family of -free graphs with edges and without isolated vertices. Let $S…
math.CO2024
A sharp upper bound on the spectral radius of -free graphs with given size
Yuxiang Liu, Ligong Wang
A graph is -free if does not contain as a subgraph. Let be the spectral radius of a graph . Let denote the theta graph, which is obtained by c…
math.CO2024
Maxima of the -index of 2 leaves-free graphs with given size
Yuxiang Liu, Ligong Wang, Xiaolong Jia
The -index of graph is the largest eigenvalue of the signless Laplacian matrix of . Wang [Discrete Appl. Math. 356(2024)] proved the sharp upper bounds on the -index o…