{"title":"外-1-平面图的入射着色","authors":"Meng-ke Qi, Xin Zhang","doi":"10.1007/s10255-024-1126-3","DOIUrl":null,"url":null,"abstract":"<div><p>A graph is outer-1-planar if it can be drawn in the plane so that all vertices lie on the outer-face and each edge crosses at most one another edge. It is known that every outer-1-planar graph is a planar partial 3-tree. In this paper, we conjecture that every planar graph <i>G</i> has a proper incidence (Δ(<i>G</i>) + 2)-coloring and confirm it for outer-1-planar graphs with maximum degree at least 8 or with girth at least 4. Specifically, we prove that every outer-1-planar graph <i>G</i> has an incidence (Δ(<i>G</i>) + 3, 2)-coloring, and every outer-1-planar graph <i>G</i> with maximum degree at least 8 or with girth at least 4 has an incidence (Δ(<i>G</i>) + 2, 2)-coloring.</p></div>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Incidence Coloring of Outer-1-planar Graphs\",\"authors\":\"Meng-ke Qi, Xin Zhang\",\"doi\":\"10.1007/s10255-024-1126-3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A graph is outer-1-planar if it can be drawn in the plane so that all vertices lie on the outer-face and each edge crosses at most one another edge. It is known that every outer-1-planar graph is a planar partial 3-tree. In this paper, we conjecture that every planar graph <i>G</i> has a proper incidence (Δ(<i>G</i>) + 2)-coloring and confirm it for outer-1-planar graphs with maximum degree at least 8 or with girth at least 4. Specifically, we prove that every outer-1-planar graph <i>G</i> has an incidence (Δ(<i>G</i>) + 3, 2)-coloring, and every outer-1-planar graph <i>G</i> with maximum degree at least 8 or with girth at least 4 has an incidence (Δ(<i>G</i>) + 2, 2)-coloring.</p></div>\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2024-06-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10255-024-1126-3\",\"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://link.springer.com/article/10.1007/s10255-024-1126-3","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
如果一个图形可以在平面上绘制,使得所有顶点都位于外面上,并且每条边最多与另一条边交叉,那么这个图形就是外-1-平面图形。众所周知,每个外-1-平面图都是一个平面局部 3 树。在本文中,我们猜想每个平面图 G 都有一个适当的入射 (Δ(G) + 2)- 着色,并针对最大度数至少为 8 或周长至少为 4 的外-1 平面图证实了这一猜想。具体地说,我们证明了每一个外-1-平面图 G 都有一个入射 (Δ(G) + 3, 2)-着色,而每一个最大度数至少为 8 或周长至少为 4 的外-1-平面图 G 都有一个入射 (Δ(G) + 2, 2)-着色。
A graph is outer-1-planar if it can be drawn in the plane so that all vertices lie on the outer-face and each edge crosses at most one another edge. It is known that every outer-1-planar graph is a planar partial 3-tree. In this paper, we conjecture that every planar graph G has a proper incidence (Δ(G) + 2)-coloring and confirm it for outer-1-planar graphs with maximum degree at least 8 or with girth at least 4. Specifically, we prove that every outer-1-planar graph G has an incidence (Δ(G) + 3, 2)-coloring, and every outer-1-planar graph G with maximum degree at least 8 or with girth at least 4 has an incidence (Δ(G) + 2, 2)-coloring.