{"title":"1-2猜想适用于正则图","authors":"Kecai Deng , Hongyuan Qiu","doi":"10.1016/j.jctb.2025.05.002","DOIUrl":null,"url":null,"abstract":"<div><div>The 1-2 conjecture asserts that the vertices and edges of every graph can be assigned with weights in <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>}</mo></math></span> such that adjacent vertices receive distinct weighted degrees. While this conjecture remains open in general, it has been proven that it is possible to achieve this using the weight set <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>}</mo></math></span>. We demonstrate that the weight set <span><math><mo>{</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>}</mo></math></span> suffices for every graph. As a corollary, the 1-2 conjecture is confirmed for regular graphs. Additionally, we verify another related conjecture concerning locally irregular total colouring, for regular graphs.</div></div>","PeriodicalId":54865,"journal":{"name":"Journal of Combinatorial Theory Series B","volume":"174 ","pages":"Pages 207-213"},"PeriodicalIF":1.2000,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The 1-2 conjecture holds for regular graphs\",\"authors\":\"Kecai Deng , Hongyuan Qiu\",\"doi\":\"10.1016/j.jctb.2025.05.002\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The 1-2 conjecture asserts that the vertices and edges of every graph can be assigned with weights in <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>}</mo></math></span> such that adjacent vertices receive distinct weighted degrees. While this conjecture remains open in general, it has been proven that it is possible to achieve this using the weight set <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mn>3</mn><mo>}</mo></math></span>. We demonstrate that the weight set <span><math><mo>{</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>}</mo></math></span> suffices for every graph. As a corollary, the 1-2 conjecture is confirmed for regular graphs. Additionally, we verify another related conjecture concerning locally irregular total colouring, for regular graphs.</div></div>\",\"PeriodicalId\":54865,\"journal\":{\"name\":\"Journal of Combinatorial Theory Series B\",\"volume\":\"174 \",\"pages\":\"Pages 207-213\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2025-05-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Combinatorial Theory Series B\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0095895625000371\",\"RegionNum\":1,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Combinatorial Theory Series B","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0095895625000371","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
The 1-2 conjecture asserts that the vertices and edges of every graph can be assigned with weights in such that adjacent vertices receive distinct weighted degrees. While this conjecture remains open in general, it has been proven that it is possible to achieve this using the weight set . We demonstrate that the weight set suffices for every graph. As a corollary, the 1-2 conjecture is confirmed for regular graphs. Additionally, we verify another related conjecture concerning locally irregular total colouring, for regular graphs.
期刊介绍:
The Journal of Combinatorial Theory publishes original mathematical research dealing with theoretical and physical aspects of the study of finite and discrete structures in all branches of science. Series B is concerned primarily with graph theory and matroid theory and is a valuable tool for mathematicians and computer scientists.