Yaojun Chen

collaborators

7 papers

math.CO2023

Ramsey goodness of fans

Yanbo Zhang, Yaojun Chen

Given two graphs $G_{1}$ and $G_{2}$ , the Ramsey number $r (G_{1}, G_{2})$ refers to the smallest positive integer $N$ such that any graph $G$ with $N$ vertices contains $G_{1}$ as a subgraph,…

math.CO2023

Maximum cliques in a graph without disjoint given subgraph

Fangfang Zhang, Yaojun Chen, Ervin Gyori +1

The generalized Turán number $\ex(n,K_s,F)$ denotes the maximum number of copies of $K_{s}$ in an $n$ -vertex $F$ -free graph. Let $k F$ denote $k$ disjoint copies of $F$ . Gerbner, Meth…

math.CO2023

Extremal problems for a matching and any other graph

Xiutao Zhu, Yaojun Chen

For a family of graphs $\F$, a graph is called $\F$-free if it does not contain any member of $\F$ as a subgraph. The generalized Turán number $\ex(n,K_r,\F)$ is the maximum number…

math.CO2023

The hat guessing number of random graphs with constant edge-chosen probability

Lanchao Wang, Yaojun Chen

Let $G$ be a graph with $n$ vertices. The {\em hat guessing number} of $G$ is defined in terms of the following game: There are $n$ players and one opponent. The opponent will wear…

math.CO2023

Connectedness of friends-and-strangers graphs of complete bipartite graphs and others

Lanchao Wang, Junying Lu, Yaojun Chen

Let $X$ and $Y$ be any two graphs of order $n$ . The friends-and-strangers graph $FS (X, Y)$ of $X$ and $Y$ is a graph with vertex set consisting of all bijections $σ:V(X) \m…

math.CO2022

Connectivity of friends-and-strangers graphs on random pairs

Lanchao Wang, Yaojun Chen

Consider two graphs $X$ and $Y$ , each with $n$ vertices. The friends-and-strangers graph $FS (X, Y)$ of $X$ and $Y$ is a graph with vertex set consisting of all bijections $…