Communications on Applied Mathematics and Computation ›› 2025, Vol. 7 ›› Issue (4): 1333-1349.doi: 10.1007/s42967-023-00316-3

• ORIGINAL PAPERS • 上一篇    下一篇

Ramsey Numbers of Stars Versus Generalised Wheels

Yiran Zhang, Yuejian Peng   

  1. School of Mathematics, Hunan University, Changsha, 410082, Hunan, China
  • 收稿日期:2023-02-12 修回日期:2023-09-02 接受日期:2023-09-11 出版日期:2024-02-05 发布日期:2024-02-05
  • 通讯作者: Yuejian Peng,E-mail:ypeng1@hnu.edu.cn E-mail:ypeng1@hnu.edu.cn
  • 作者简介:Yiran Zhang, E-mail:zhangyiran1125@163.com
  • 基金资助:
    This work was supported by the NSFC (Grant no. 11931002).

Ramsey Numbers of Stars Versus Generalised Wheels

Yiran Zhang, Yuejian Peng   

  1. School of Mathematics, Hunan University, Changsha, 410082, Hunan, China
  • Received:2023-02-12 Revised:2023-09-02 Accepted:2023-09-11 Online:2024-02-05 Published:2024-02-05
  • Supported by:
    This work was supported by the NSFC (Grant no. 11931002).

摘要: For two graphs $G$ and $H$, the Ramsey number $R(G, H)$ is the smallest integer $n$ such that for any $n$-vertex graph, either it contains $G$ or its complement contains $H$. Let $S_n$ be a star of order $n$ and $W_{s, m}$ be a generalised wheel $K_s \vee C_m$. Previous studies by Wang and Chen (Graphs Comb 35(1):189-193, 2019) and Chng et al. (Discret Math 344(8):112440, 2021) imply that a tree is $W_{s, 4^{-}}$good, $W_{s, 5^{-}}$good, $W_{s, 6}$-good, and $W_{s, 7^{-}}$good for $s \geqslant 2$. In this paper, we study the Ramsey numbers $R\left(S_n, W_{s, 8}\right)$, and our results indicate that trees are not always $W_{s, 8}$-good.

关键词: Ramsey number, Star, Generalised wheel

Abstract: For two graphs $G$ and $H$, the Ramsey number $R(G, H)$ is the smallest integer $n$ such that for any $n$-vertex graph, either it contains $G$ or its complement contains $H$. Let $S_n$ be a star of order $n$ and $W_{s, m}$ be a generalised wheel $K_s \vee C_m$. Previous studies by Wang and Chen (Graphs Comb 35(1):189-193, 2019) and Chng et al. (Discret Math 344(8):112440, 2021) imply that a tree is $W_{s, 4^{-}}$good, $W_{s, 5^{-}}$good, $W_{s, 6}$-good, and $W_{s, 7^{-}}$good for $s \geqslant 2$. In this paper, we study the Ramsey numbers $R\left(S_n, W_{s, 8}\right)$, and our results indicate that trees are not always $W_{s, 8}$-good.

Key words: Ramsey number, Star, Generalised wheel

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