{"title":"$$K_4$$ 小自由图的注入色度指数","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":"{\"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}","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
摘要
如果对于任意两条不同的边\(e_1\)和\(e_2\)来说,如果它们在 G 中的距离是 2 或者在一个共同的三角形中,那么它们的颜色就是不同的,那么图 G 的边着色就是可注入的。G 的注入色度指数((\chi ^\prime _{inj}(G)\))是 G 的注入边着色所需的最少颜色数。在本说明中,我们证明了每个具有最大度的\(\Delta (G)\ge 3\) 的\(K_4\)-minor free graph G 都满足\(\chi ^\prime _{inj}(G)\le 2\Delta (G)+1\)。
Injective Chromatic Index of $$K_4$$ -Minor Free Graphs
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 \(\chi ^\prime _{inj}(G)\le 2\Delta (G)+1\).