Yanbo Zhang

activity

20242026

collaborators

8 papers

math.CO2026

Online Ramsey numbers of the claw versus cycles

Hexuan Zhi, Yanbo Zhang

The online Ramsey number $r ~ (G, H)$ is defined via a Builder--Painter game on an empty graph with countably many vertices. In each round, Builder reveals an edge, which Painte…

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

Ramsey goodness of stars and fans for the Hajós graph

Jiafu He, Haiyu Zeng, Yanbo Zhang

Given two graphs $G_{1}$ and $G_{2}$ , the Ramsey number $R (G_{1}, G_{2})$ denotes the smallest integer $N$ such that any red-blue coloring of the edges of $K_{N}$ contains either a red $G_{1}$ …

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…

Online Ramsey numbers of the claw versus cycles

Fan-goodness of sparse graphs

Ramsey numbers of sparse graphs versus disjoint books

Minimum degree and sparse connected spanning subgraphs

Ramsey goodness of stars and fans for the Hajós graph

Trichotomy and tKm​-goodness of sparse graphs

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