江汉大学学报(自然科学版) ›› 2025, Vol. 53 ›› Issue (3): 20-26.doi: 10.16389/j.cnki.cn42-1737/n.2025.03.003

• 数学 • 上一篇    

无{ P4 ∪ P2,( K1 ∪ K2 )+ Kp}图类的χ界定函数

唐玲香 a,秦晓晓 a,张静洁 a,火博丰 *a,b,c   

  1. 青海师范大学 a.数学与统计学院;b. 高原科学与可持续发展研究院; c. 藏语智能信息处理及应用国家重点实验室,青海 西宁 810000
  • 发布日期:2025-06-30
  • 通讯作者: 火博丰
  • 作者简介:唐玲香(1999—),女,硕士生,研究方向:图论与组合优化。
  • 基金资助:
    青海省自然科学基金项目(11961055)

χ-binding Function of{P4 ∪ P2 ,(K1 ∪K2 )+ Kp }-free Graphs

TANG Lingxiang,QIN Xiaoxiao,ZHANG Jingjie,HUO Bofeng   

  1. a. School of Mathematics and Statistics;b. Academy of Plateau Science and Sustainability;c. The State Key Laboratory of Tibetan Intelligent Information Processing and Application,Qinghai Normal University, Xining 810000,Qinghai,China
  • Published:2025-06-30
  • Contact: HUO Bofeng

摘要: 设ɠ是一个图类,如果存在一个函数f使得对任意G∈ɠ,都有χ(G)≤ f (ω(G)),那么ɠ 就是χ有界的,并且称f是χ界定函数。近几年来,有很多学者开始研究禁用子图类的χ有界性, 其中无2K2 图类得到了广泛的研究。众所周知,无P4 ∪ P2 图类是无2K2 图类的母图,针对这个 图给出了一个结果,证明了无{P4 ∪ P2 ,(K1 ∪ K2 ) +Kp }图类的一个χ界定函数。

关键词: P4 ∪ P2, 色数, 团数

Abstract: Let ɠ be a graph class,if there is a function f such that χ(G)≤ f(ω(G))for every G ∈ ɠ,then ɠ is χ-bounded,and f is said to be a χ-binding function. In recent years,many scholars have begun to study the χ-boundedness of forbidden subgraph classes,among which 2K2-free graph classes have been widely studied. As is well known, {P4 ∪P2 }-free graph classes are supergraphs of 2K2-free graph classes. In this paper,we give a result on this graph and prove a χ-binding function of{P4 ∪ P2 ,(K1 ∪ K2 )+ Kp } free graph classes.

Key words: P4 ∪P2, chromatic number, clique number

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