{"title":"超越平面性的图形的公平着色","authors":"Weichan Liu","doi":"10.1016/j.dam.2025.10.020","DOIUrl":null,"url":null,"abstract":"<div><div>An equitable coloring of a graph is a proper coloring where the sizes of any two different color classes do not differ by more than one. A graph is IC-planar if it can be drawn in the plane so that no two crossed edges have a common endpoint, and is NIC-planar graph if it can be embedded in the plane in such a way that no two pairs of crossed edges share two endpoints. Zhang, Wang, and Xu proved that every IC-planar graph with maximum degree <span><math><mrow><mi>Δ</mi><mo>≥</mo><mn>12</mn></mrow></math></span> and every NIC-planar graph with maximum degree <span><math><mrow><mi>Δ</mi><mo>≥</mo><mn>13</mn></mrow></math></span> have equitable <span><math><mi>Δ</mi></math></span>-colorings. In this paper, we reduce the threshold from 12 to 10 for IC-planar graphs and from 13 to 11 for NIC-planar graphs.</div></div>","PeriodicalId":50573,"journal":{"name":"Discrete Applied Mathematics","volume":"379 ","pages":"Pages 685-693"},"PeriodicalIF":1.0000,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Equitable coloring of graphs beyond planarity\",\"authors\":\"Weichan Liu\",\"doi\":\"10.1016/j.dam.2025.10.020\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>An equitable coloring of a graph is a proper coloring where the sizes of any two different color classes do not differ by more than one. A graph is IC-planar if it can be drawn in the plane so that no two crossed edges have a common endpoint, and is NIC-planar graph if it can be embedded in the plane in such a way that no two pairs of crossed edges share two endpoints. Zhang, Wang, and Xu proved that every IC-planar graph with maximum degree <span><math><mrow><mi>Δ</mi><mo>≥</mo><mn>12</mn></mrow></math></span> and every NIC-planar graph with maximum degree <span><math><mrow><mi>Δ</mi><mo>≥</mo><mn>13</mn></mrow></math></span> have equitable <span><math><mi>Δ</mi></math></span>-colorings. In this paper, we reduce the threshold from 12 to 10 for IC-planar graphs and from 13 to 11 for NIC-planar graphs.</div></div>\",\"PeriodicalId\":50573,\"journal\":{\"name\":\"Discrete Applied Mathematics\",\"volume\":\"379 \",\"pages\":\"Pages 685-693\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2025-10-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Discrete Applied Mathematics\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0166218X25005839\",\"RegionNum\":3,\"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":"Discrete Applied Mathematics","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166218X25005839","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
An equitable coloring of a graph is a proper coloring where the sizes of any two different color classes do not differ by more than one. A graph is IC-planar if it can be drawn in the plane so that no two crossed edges have a common endpoint, and is NIC-planar graph if it can be embedded in the plane in such a way that no two pairs of crossed edges share two endpoints. Zhang, Wang, and Xu proved that every IC-planar graph with maximum degree and every NIC-planar graph with maximum degree have equitable -colorings. In this paper, we reduce the threshold from 12 to 10 for IC-planar graphs and from 13 to 11 for NIC-planar graphs.
期刊介绍:
The aim of Discrete Applied Mathematics is to bring together research papers in different areas of algorithmic and applicable discrete mathematics as well as applications of combinatorial mathematics to informatics and various areas of science and technology. Contributions presented to the journal can be research papers, short notes, surveys, and possibly research problems. The "Communications" section will be devoted to the fastest possible publication of recent research results that are checked and recommended for publication by a member of the Editorial Board. The journal will also publish a limited number of book announcements as well as proceedings of conferences. These proceedings will be fully refereed and adhere to the normal standards of the journal.
Potential authors are advised to view the journal and the open calls-for-papers of special issues before submitting their manuscripts. Only high-quality, original work that is within the scope of the journal or the targeted special issue will be considered.