Yaojun Chen

collaborators

8 papers

math.CO2025

Oriented trees in digraphs with large girth

Junying Lu, Yaojun Chen

The girth of a graph $G$ is the length of a shortest cycle of $G$ . Jiang (JCT-B, 2001) showed that every graph $G$ with girth at least $2 ℓ + 1$ and minimum degree at least $k/\ell…

math.CO2025

Oriented diameter of graphs with given domination number

Xiaolin Wang, Yaojun Chen

Let $G$ be a connected bridgeless graph with domination number $γ$ . The oriented diameter (strong diameter) of $G$ is the smallest integer $d$ for which $G$ admits a strong orienta…

math.CO2025

Fan-goodness of sparse graphs

Ting Huang, Yanbo Zhang, Yaojun Chen

Let $G$ be a connected graph of order $n$ , $F_{k}$ be a fan consisting of $k$ triangles sharing a common vertex, and $t F_{k}$ be $t$ vertex-disjoint copies of $F_{k}$ . Brennan (2017) sho…

math.CO2025

Ramsey numbers of sparse graphs versus disjoint books

Ting Huang, Yanbo Zhang, Yaojun Chen

Let $B_{k}$ denote a book on $k + 2$ vertices and $t B_{k}$ be $t$ vertex-disjoint $B_{k}$ 's. Let $G$ be a connected graph with $n$ vertices and at most $n (1 + ε)$ edges, where $ε$ is a const…

math.CO2025

Minimum degree and sparse connected spanning subgraphs

Ting Huang, Yanbo Zhang, Yaojun Chen

Let $G$ be a connected graph on $n$ vertices and at most $n (1 + ε)$ edges with bounded maximum degree, and $F$ a graph on $n$ vertices with minimum degree at least $n - k$ , where $ε$ i…

math.CO2025

Trichotomy and $t K_{m}$ -goodness of sparse graphs

Yanbo Zhang, Yaojun Chen

Let $G$ be a connected graph with $n$ vertices and $n + k - 2$ edges and $t K_{m}$ denote the disjoint union of $t$ complete graphs $K_{m}$ . In this paper, by developing a trichotomy for sp…

Oriented trees in digraphs with large girth

Oriented diameter of graphs with given domination number

Fan-goodness of sparse graphs

Ramsey numbers of sparse graphs versus disjoint books

Minimum degree and sparse connected spanning subgraphs

Trichotomy and tKm​-goodness of sparse graphs

Trichotomy and $t K_{m}$ -goodness of sparse graphs