{"title":"p偶的Kr×p的公平总色数","authors":"Anderson G. da Silva, Simone Dantas, Diana Sasaki","doi":"10.1016/j.entcs.2019.08.060","DOIUrl":null,"url":null,"abstract":"<div><p>A total coloring is equitable if the number of elements colored by any two distinct colors differs by at most one. The equitable total chromatic number of a graph <span><math><mo>(</mo><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>)</mo></math></span> is the smallest integer for which the graph has an equitable total coloring. Wang (2002) conjectured that <span><math><mi>Δ</mi><mo>+</mo><mn>1</mn><mo>≤</mo><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>2</mn></math></span>. In 1994, Fu proved that there exist equitable (Δ + 2)-total colorings for all complete <em>r</em>-partite <em>p</em>-balanced graphs of odd order. For the even case, he determined that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>3</mn></math></span>. Silva, Dantas and Sasaki (2018) verified Wang's conjecture when <em>G</em> is a complete <em>r</em>-partite <em>p</em>-balanced graph, showing that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>=</mo><mi>Δ</mi><mo>+</mo><mn>1</mn></math></span> if <em>G</em> has odd order, and <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>2</mn></math></span> if <em>G</em> has even order. In this work we improve this bound by showing that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>=</mo><mi>Δ</mi><mo>+</mo><mn>1</mn></math></span> when <em>G</em> is a complete <em>r</em>-partite <em>p</em>-balanced graph with <em>r</em> ≥ 4 even and <em>p</em> even, and for <em>r</em> odd and <em>p</em> even.</p></div>","PeriodicalId":38770,"journal":{"name":"Electronic Notes in Theoretical Computer Science","volume":"346 ","pages":"Pages 685-697"},"PeriodicalIF":0.0000,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.entcs.2019.08.060","citationCount":"1","resultStr":"{\"title\":\"Equitable Total Chromatic Number of Kr×p for p Even\",\"authors\":\"Anderson G. da Silva, Simone Dantas, Diana Sasaki\",\"doi\":\"10.1016/j.entcs.2019.08.060\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>A total coloring is equitable if the number of elements colored by any two distinct colors differs by at most one. The equitable total chromatic number of a graph <span><math><mo>(</mo><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>)</mo></math></span> is the smallest integer for which the graph has an equitable total coloring. Wang (2002) conjectured that <span><math><mi>Δ</mi><mo>+</mo><mn>1</mn><mo>≤</mo><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>2</mn></math></span>. In 1994, Fu proved that there exist equitable (Δ + 2)-total colorings for all complete <em>r</em>-partite <em>p</em>-balanced graphs of odd order. For the even case, he determined that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>3</mn></math></span>. Silva, Dantas and Sasaki (2018) verified Wang's conjecture when <em>G</em> is a complete <em>r</em>-partite <em>p</em>-balanced graph, showing that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>=</mo><mi>Δ</mi><mo>+</mo><mn>1</mn></math></span> if <em>G</em> has odd order, and <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>≤</mo><mi>Δ</mi><mo>+</mo><mn>2</mn></math></span> if <em>G</em> has even order. In this work we improve this bound by showing that <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>″</mo></mrow></msubsup><mo>=</mo><mi>Δ</mi><mo>+</mo><mn>1</mn></math></span> when <em>G</em> is a complete <em>r</em>-partite <em>p</em>-balanced graph with <em>r</em> ≥ 4 even and <em>p</em> even, and for <em>r</em> odd and <em>p</em> even.</p></div>\",\"PeriodicalId\":38770,\"journal\":{\"name\":\"Electronic Notes in Theoretical Computer Science\",\"volume\":\"346 \",\"pages\":\"Pages 685-697\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-08-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.entcs.2019.08.060\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Electronic Notes in Theoretical Computer Science\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1571066119301112\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"Computer Science\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electronic Notes in Theoretical Computer Science","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1571066119301112","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Computer Science","Score":null,"Total":0}
Equitable Total Chromatic Number of Kr×p for p Even
A total coloring is equitable if the number of elements colored by any two distinct colors differs by at most one. The equitable total chromatic number of a graph is the smallest integer for which the graph has an equitable total coloring. Wang (2002) conjectured that . In 1994, Fu proved that there exist equitable (Δ + 2)-total colorings for all complete r-partite p-balanced graphs of odd order. For the even case, he determined that . Silva, Dantas and Sasaki (2018) verified Wang's conjecture when G is a complete r-partite p-balanced graph, showing that if G has odd order, and if G has even order. In this work we improve this bound by showing that when G is a complete r-partite p-balanced graph with r ≥ 4 even and p even, and for r odd and p even.
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