Operations Research Transactions ›› 2025, Vol. 29 ›› Issue (1): 225-231.doi: 10.15960/j.cnki.issn.1007-6093.2025.01.019

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The lower limit of the independence number in edge chromatic critical graphs

Linming QI1,*(), Weiliang ZHAO1, Lianying MIAO2   

  1. 1. Zhejiang Industry Polytechnic College, Shaoxing 312000, Zhejiang, China
    2. School of Mathematics and Science, Nanjing Normal University, Nanjing 210023, Jiangsu, China
  • Received:2021-10-21 Online:2025-03-15 Published:2025-03-08
  • Contact: Linming QI E-mail:qilinmingxr@163.com

Abstract:

In 1968, Vizing conjectured for any edge chromatic critical graph $G$ with maximum degree $\Delta$ and independence number $\alpha(G)$, $\alpha(G)\leqslant\dfrac{n}{2}$. This conjecture is still open. In this paper, we proved that $\alpha(G)\leqslant\dfrac{7\Delta-6}{12\Delta-6}|V|$ for $\Delta\in\{3, 4, 5, 6\} $ and $\alpha(G)\leqslant \dfrac{4\Delta-3}{7\Delta-3}|V|$ for $\Delta\in\{7, 8, 9\}$.

Key words: edge coloring, critical graphs, independence number

CLC Number: