{"title":"一种证明图的支配唯一性的新方法","authors":"Gee Choon Lau","doi":"10.1016/j.jaubas.2017.03.003","DOIUrl":null,"url":null,"abstract":"<div><p>Let <em>G</em> be a graph of order <em>n</em>. A subset <em>S</em> of <span><math><mrow><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow></math></span> is a dominating set of <em>G</em> if every vertex in <span><math><mrow><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>⧹</mo><mi>S</mi></mrow></math></span> is adjacent to at least one vertex of <em>S</em>. The domination polynomial of <em>G</em> is the polynomial <span><math><mrow><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mi>γ</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mrow><mi>n</mi></mrow></msubsup><mi>d</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>i</mi><mo>)</mo><msup><mrow><mi>x</mi></mrow><mrow><mi>i</mi></mrow></msup></mrow></math></span>, where <span><math><mrow><mi>d</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>i</mi><mo>)</mo></mrow></math></span> is the number of dominating sets of <em>G</em> of size <em>i</em>, and <span><math><mrow><mi>γ</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow></math></span> is the size of a smallest dominating set of <em>G</em>, called the domination number of <em>G</em>. We say two graphs <em>G</em> and <em>H</em> are <em>dominating equivalent</em> if <span><math><mrow><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><mi>D</mi><mo>(</mo><mi>H</mi><mtext>,</mtext><mi>x</mi><mo>)</mo></mrow></math></span>. A graph <em>G</em> is said to be <em>dominating unique</em>, or simply <span><math><mrow><mi>D</mi></mrow></math></span>-unique, if <span><math><mrow><mi>D</mi><mo>(</mo><mi>H</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo></mrow></math></span> implies that <span><math><mrow><mi>H</mi><mspace></mspace><mo>≅</mo><mspace></mspace><mi>G</mi></mrow></math></span>. The goal of this paper is to find a new approach to determine the dominating uniqueness of graphs. In this paper, we define a new graph polynomial, called star polynomial, and introduced an analogy notion of star uniqueness of graphs. As an application, if <em>G</em> is a graph without isolated vertices, we show that a graph <em>G</em> is star unique if and only if <span><math><mrow><mover><mrow><mi>G</mi></mrow><mrow><mo>‾</mo></mrow></mover><mi>∨</mi><msub><mrow><mi>K</mi></mrow><mrow><mi>m</mi></mrow></msub></mrow></math></span> is dominating unique for each <span><math><mrow><mi>m</mi><mspace></mspace><mo>⩾</mo><mspace></mspace><mn>0</mn></mrow></math></span>. As a by-product, the dominating uniqueness of many families of dense graphs is also determined.</p></div>","PeriodicalId":17232,"journal":{"name":"Journal of the Association of Arab Universities for Basic and Applied Sciences","volume":"24 ","pages":"Pages 292-299"},"PeriodicalIF":0.0000,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.jaubas.2017.03.003","citationCount":"0","resultStr":"{\"title\":\"A new method for proving dominating uniqueness of graphs\",\"authors\":\"Gee Choon Lau\",\"doi\":\"10.1016/j.jaubas.2017.03.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Let <em>G</em> be a graph of order <em>n</em>. A subset <em>S</em> of <span><math><mrow><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow></math></span> is a dominating set of <em>G</em> if every vertex in <span><math><mrow><mi>V</mi><mo>(</mo><mi>G</mi><mo>)</mo><mo>⧹</mo><mi>S</mi></mrow></math></span> is adjacent to at least one vertex of <em>S</em>. The domination polynomial of <em>G</em> is the polynomial <span><math><mrow><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><msubsup><mrow><mo>∑</mo></mrow><mrow><mi>i</mi><mo>=</mo><mi>γ</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow><mrow><mi>n</mi></mrow></msubsup><mi>d</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>i</mi><mo>)</mo><msup><mrow><mi>x</mi></mrow><mrow><mi>i</mi></mrow></msup></mrow></math></span>, where <span><math><mrow><mi>d</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>i</mi><mo>)</mo></mrow></math></span> is the number of dominating sets of <em>G</em> of size <em>i</em>, and <span><math><mrow><mi>γ</mi><mo>(</mo><mi>G</mi><mo>)</mo></mrow></math></span> is the size of a smallest dominating set of <em>G</em>, called the domination number of <em>G</em>. We say two graphs <em>G</em> and <em>H</em> are <em>dominating equivalent</em> if <span><math><mrow><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><mi>D</mi><mo>(</mo><mi>H</mi><mtext>,</mtext><mi>x</mi><mo>)</mo></mrow></math></span>. A graph <em>G</em> is said to be <em>dominating unique</em>, or simply <span><math><mrow><mi>D</mi></mrow></math></span>-unique, if <span><math><mrow><mi>D</mi><mo>(</mo><mi>H</mi><mtext>,</mtext><mi>x</mi><mo>)</mo><mo>=</mo><mi>D</mi><mo>(</mo><mi>G</mi><mtext>,</mtext><mi>x</mi><mo>)</mo></mrow></math></span> implies that <span><math><mrow><mi>H</mi><mspace></mspace><mo>≅</mo><mspace></mspace><mi>G</mi></mrow></math></span>. The goal of this paper is to find a new approach to determine the dominating uniqueness of graphs. In this paper, we define a new graph polynomial, called star polynomial, and introduced an analogy notion of star uniqueness of graphs. As an application, if <em>G</em> is a graph without isolated vertices, we show that a graph <em>G</em> is star unique if and only if <span><math><mrow><mover><mrow><mi>G</mi></mrow><mrow><mo>‾</mo></mrow></mover><mi>∨</mi><msub><mrow><mi>K</mi></mrow><mrow><mi>m</mi></mrow></msub></mrow></math></span> is dominating unique for each <span><math><mrow><mi>m</mi><mspace></mspace><mo>⩾</mo><mspace></mspace><mn>0</mn></mrow></math></span>. As a by-product, the dominating uniqueness of many families of dense graphs is also determined.</p></div>\",\"PeriodicalId\":17232,\"journal\":{\"name\":\"Journal of the Association of Arab Universities for Basic and Applied Sciences\",\"volume\":\"24 \",\"pages\":\"Pages 292-299\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2017-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.jaubas.2017.03.003\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of the Association of Arab Universities for Basic and Applied Sciences\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1815385217300160\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Association of Arab Universities for Basic and Applied Sciences","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1815385217300160","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
A new method for proving dominating uniqueness of graphs
Let G be a graph of order n. A subset S of is a dominating set of G if every vertex in is adjacent to at least one vertex of S. The domination polynomial of G is the polynomial , where is the number of dominating sets of G of size i, and is the size of a smallest dominating set of G, called the domination number of G. We say two graphs G and H are dominating equivalent if . A graph G is said to be dominating unique, or simply -unique, if implies that . The goal of this paper is to find a new approach to determine the dominating uniqueness of graphs. In this paper, we define a new graph polynomial, called star polynomial, and introduced an analogy notion of star uniqueness of graphs. As an application, if G is a graph without isolated vertices, we show that a graph G is star unique if and only if is dominating unique for each . As a by-product, the dominating uniqueness of many families of dense graphs is also determined.