{"title":"Injective Chromatic Index of $$K_4$$ -Minor Free Graphs","authors":"Jian-Bo Lv, Jiacong Fu, Jianxi Li","doi":"10.1007/s00373-024-02807-3","DOIUrl":null,"url":null,"abstract":"<p>An edge-coloring of a graph <i>G</i> is <i>injective</i> if for any two distinct edges <span>\\(e_1\\)</span> and <span>\\(e_2\\)</span>, the colors of <span>\\(e_1\\)</span> and <span>\\(e_2\\)</span> are distinct if they are at distance 2 in <i>G</i> or in a common triangle. The injective chromatic index of <i>G</i>, <span>\\(\\chi ^\\prime _{inj}(G)\\)</span>, is the minimum number of colors needed for an injective edge-coloring of <i>G</i>. In this note, we show that every <span>\\(K_4\\)</span>-minor free graph <i>G</i> with maximum degree <span>\\(\\Delta (G)\\ge 3\\)</span> satisfies <span>\\(\\chi ^\\prime _{inj}(G)\\le 2\\Delta (G)+1\\)</span>.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1007/s00373-024-02807-3","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
An edge-coloring of a graph G is injective if for any two distinct edges \(e_1\) and \(e_2\), the colors of \(e_1\) and \(e_2\) are distinct if they are at distance 2 in G or in a common triangle. The injective chromatic index of G, \(\chi ^\prime _{inj}(G)\), is the minimum number of colors needed for an injective edge-coloring of G. In this note, we show that every \(K_4\)-minor free graph G with maximum degree \(\Delta (G)\ge 3\) satisfies \(\chi ^\prime _{inj}(G)\le 2\Delta (G)+1\).