3 papers
math.CO2022
Graphs with many independent vertex cuts
Yanan Hu, Xingzhi Zhan, Leilei Zhang
The cycles are the only -connected graphs in which any two nonadjacent vertices form a vertex cut. We generalize this fact by proving that for every integer there exist…
math.CO2021
On almost self-centered graphs and almost peripheral graphs
Yanan Hu, Xingzhi Zhan
An almost self-centered graph is a connected graph of order with exactly central vertices, and an almost peripheral graph is a connected graph of order with exactly $…
math.CO2020
Possible cardinalities of the center of a graph
Yanan Hu, Xingzhi Zhan
A central vertex of a graph is a vertex whose eccentricity equals the radius. The center of a graph is the set of all central vertices. The central ratio of a graph is the ratio of…