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{"title":"具有大最大度的全着色图","authors":"Aseem Dalal, Jessica McDonald, Songling Shan","doi":"10.1002/jgt.23268","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>We prove that for any graph <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math>, the total chromatic number of <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> is at most <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>Δ</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>+</mo>\n \n <mn>2</mn>\n \n <mfenced>\n <mfrac>\n <mrow>\n <mo>|</mo>\n \n <mi>V</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>|</mo>\n </mrow>\n \n <mrow>\n <mi>Δ</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>+</mo>\n \n <mn>1</mn>\n </mrow>\n </mfrac>\n </mfenced>\n </mrow>\n </mrow>\n </semantics></math>. This saves one color in comparison with the result of Hind from 1992. In particular, our result says that if <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>Δ</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>≥</mo>\n \n <mfrac>\n <mn>1</mn>\n \n <mn>2</mn>\n </mfrac>\n \n <mo>|</mo>\n \n <mi>V</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>|</mo>\n </mrow>\n </mrow>\n </semantics></math>, then <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> has a total coloring using at most <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>Δ</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>+</mo>\n \n <mn>4</mn>\n </mrow>\n </mrow>\n </semantics></math> colors. When <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> is regular and has a sufficient number of vertices, we can actually save an additional two colors. Specifically, we prove that for any <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mn>0</mn>\n \n <mo><</mo>\n \n <mi>ε</mi>\n \n <mo><</mo>\n \n <mn>1</mn>\n </mrow>\n </mrow>\n </semantics></math>, there exists <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msub>\n <mi>n</mi>\n \n <mn>0</mn>\n </msub>\n \n <mo>∈</mo>\n \n <mi>N</mi>\n </mrow>\n </mrow>\n </semantics></math> such that: if <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math> is an <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>r</mi>\n </mrow>\n </mrow>\n </semantics></math>-regular graph on <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>n</mi>\n \n <mo>≥</mo>\n \n <msub>\n <mi>n</mi>\n \n <mn>0</mn>\n </msub>\n </mrow>\n </mrow>\n </semantics></math> vertices with <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>r</mi>\n \n <mo>≥</mo>\n \n <mfrac>\n <mn>1</mn>\n \n <mn>2</mn>\n </mfrac>\n \n <mrow>\n <mo>(</mo>\n \n <mrow>\n <mn>1</mn>\n \n <mo>+</mo>\n \n <mi>ε</mi>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n \n <mi>n</mi>\n </mrow>\n </mrow>\n </semantics></math>, then <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <msub>\n <mi>χ</mi>\n \n <mi>T</mi>\n </msub>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>≤</mo>\n \n <mi>Δ</mi>\n \n <mrow>\n <mo>(</mo>\n \n <mi>G</mi>\n \n <mo>)</mo>\n </mrow>\n \n <mo>+</mo>\n \n <mn>2</mn>\n </mrow>\n </mrow>\n </semantics></math>. This confirms the Total Coloring Conjecture for such graphs <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>G</mi>\n </mrow>\n </mrow>\n </semantics></math>.</p>\n </div>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"110 3","pages":"249-262"},"PeriodicalIF":1.0000,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Total Coloring Graphs With Large Maximum Degree\",\"authors\":\"Aseem Dalal, Jessica McDonald, Songling Shan\",\"doi\":\"10.1002/jgt.23268\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n <p>We prove that for any graph <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>, the total chromatic number of <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> is at most <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>Δ</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>+</mo>\\n \\n <mn>2</mn>\\n \\n <mfenced>\\n <mfrac>\\n <mrow>\\n <mo>|</mo>\\n \\n <mi>V</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>|</mo>\\n </mrow>\\n \\n <mrow>\\n <mi>Δ</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>+</mo>\\n \\n <mn>1</mn>\\n </mrow>\\n </mfrac>\\n </mfenced>\\n </mrow>\\n </mrow>\\n </semantics></math>. This saves one color in comparison with the result of Hind from 1992. In particular, our result says that if <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>Δ</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>≥</mo>\\n \\n <mfrac>\\n <mn>1</mn>\\n \\n <mn>2</mn>\\n </mfrac>\\n \\n <mo>|</mo>\\n \\n <mi>V</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>|</mo>\\n </mrow>\\n </mrow>\\n </semantics></math>, then <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> has a total coloring using at most <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>Δ</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>+</mo>\\n \\n <mn>4</mn>\\n </mrow>\\n </mrow>\\n </semantics></math> colors. When <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> is regular and has a sufficient number of vertices, we can actually save an additional two colors. Specifically, we prove that for any <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mn>0</mn>\\n \\n <mo><</mo>\\n \\n <mi>ε</mi>\\n \\n <mo><</mo>\\n \\n <mn>1</mn>\\n </mrow>\\n </mrow>\\n </semantics></math>, there exists <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <msub>\\n <mi>n</mi>\\n \\n <mn>0</mn>\\n </msub>\\n \\n <mo>∈</mo>\\n \\n <mi>N</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> such that: if <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math> is an <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>r</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>-regular graph on <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>n</mi>\\n \\n <mo>≥</mo>\\n \\n <msub>\\n <mi>n</mi>\\n \\n <mn>0</mn>\\n </msub>\\n </mrow>\\n </mrow>\\n </semantics></math> vertices with <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>r</mi>\\n \\n <mo>≥</mo>\\n \\n <mfrac>\\n <mn>1</mn>\\n \\n <mn>2</mn>\\n </mfrac>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mrow>\\n <mn>1</mn>\\n \\n <mo>+</mo>\\n \\n <mi>ε</mi>\\n </mrow>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mi>n</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>, then <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <msub>\\n <mi>χ</mi>\\n \\n <mi>T</mi>\\n </msub>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>≤</mo>\\n \\n <mi>Δ</mi>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <mi>G</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n \\n <mo>+</mo>\\n \\n <mn>2</mn>\\n </mrow>\\n </mrow>\\n </semantics></math>. This confirms the Total Coloring Conjecture for such graphs <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>G</mi>\\n </mrow>\\n </mrow>\\n </semantics></math>.</p>\\n </div>\",\"PeriodicalId\":16014,\"journal\":{\"name\":\"Journal of Graph Theory\",\"volume\":\"110 3\",\"pages\":\"249-262\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2025-06-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Graph Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23268\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Graph Theory","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23268","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
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