{"title":"无短环平面图的Δ+2染色","authors":"Ying Chen, Lan Tao, Li Zhang","doi":"10.1007/s10255-023-1098-8","DOIUrl":null,"url":null,"abstract":"<div><p>A coloring of graph <i>G</i> is an <i>injective coloring</i> if its restriction to the neighborhood of any vertex is injective, which means that any two vertices get different colors if they have a common neighbor. The <i>injective chromatic number</i> χ<sub><i>i</i></sub>(<i>G</i>) of <i>G</i> is the least integer <i>k</i> such that <i>G</i> has an injective <i>k</i>-coloring. In this paper, we prove that (1) if <i>G</i> is a planar graph with girth <i>g</i> ≥ 6 and maximum degree Δ ≥ 7, then <i>χ</i><sub><i>i</i></sub>(<i>G</i>) ≤ Δ + 2; (2) if <i>G</i> is a planar graph with Δ ≥ 24 and without 3,4,7-cycles, then <i>χ</i><sub><i>i</i></sub>(<i>G</i>) ≤ Δ + 2.</p></div>","PeriodicalId":6951,"journal":{"name":"Acta Mathematicae Applicatae Sinica, English Series","volume":"39 4","pages":"1009 - 1031"},"PeriodicalIF":0.9000,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Injective Δ+2 Coloring of Planar Graph Without Short Cycles\",\"authors\":\"Ying Chen, Lan Tao, Li Zhang\",\"doi\":\"10.1007/s10255-023-1098-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A coloring of graph <i>G</i> is an <i>injective coloring</i> if its restriction to the neighborhood of any vertex is injective, which means that any two vertices get different colors if they have a common neighbor. The <i>injective chromatic number</i> χ<sub><i>i</i></sub>(<i>G</i>) of <i>G</i> is the least integer <i>k</i> such that <i>G</i> has an injective <i>k</i>-coloring. In this paper, we prove that (1) if <i>G</i> is a planar graph with girth <i>g</i> ≥ 6 and maximum degree Δ ≥ 7, then <i>χ</i><sub><i>i</i></sub>(<i>G</i>) ≤ Δ + 2; (2) if <i>G</i> is a planar graph with Δ ≥ 24 and without 3,4,7-cycles, then <i>χ</i><sub><i>i</i></sub>(<i>G</i>) ≤ Δ + 2.</p></div>\",\"PeriodicalId\":6951,\"journal\":{\"name\":\"Acta Mathematicae Applicatae Sinica, English Series\",\"volume\":\"39 4\",\"pages\":\"1009 - 1031\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2023-11-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta Mathematicae Applicatae Sinica, English Series\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10255-023-1098-8\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Mathematicae Applicatae Sinica, English Series","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s10255-023-1098-8","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
Injective Δ+2 Coloring of Planar Graph Without Short Cycles
A coloring of graph G is an injective coloring if its restriction to the neighborhood of any vertex is injective, which means that any two vertices get different colors if they have a common neighbor. The injective chromatic number χi(G) of G is the least integer k such that G has an injective k-coloring. In this paper, we prove that (1) if G is a planar graph with girth g ≥ 6 and maximum degree Δ ≥ 7, then χi(G) ≤ Δ + 2; (2) if G is a planar graph with Δ ≥ 24 and without 3,4,7-cycles, then χi(G) ≤ Δ + 2.
期刊介绍:
Acta Mathematicae Applicatae Sinica (English Series) is a quarterly journal established by the Chinese Mathematical Society. The journal publishes high quality research papers from all branches of applied mathematics, and particularly welcomes those from partial differential equations, computational mathematics, applied probability, mathematical finance, statistics, dynamical systems, optimization and management science.