{"title":"论小属曲面中 1- 嵌入图的受限匹配扩展","authors":"Jiangyue Zhang, Yan Wu, Heping Zhang","doi":"10.1016/j.disc.2024.114172","DOIUrl":null,"url":null,"abstract":"<div><p>Let <em>G</em> be a connected graph with at least <span><math><mn>2</mn><mo>(</mo><mi>m</mi><mo>+</mo><mi>n</mi><mo>+</mo><mn>1</mn><mo>)</mo></math></span> vertices that contains a perfect matching. Then <em>G</em> is <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> if for each pair of disjoint matchings <span><math><mi>M</mi><mo>,</mo><mi>N</mi><mo>⊆</mo><mi>E</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> of size <em>m</em> and <em>n</em>, respectively, there exists a perfect matching <em>F</em> in <em>G</em> such that <span><math><mi>M</mi><mo>⊆</mo><mi>F</mi></math></span> and <span><math><mi>F</mi><mo>∩</mo><mi>N</mi><mo>=</mo><mo>∅</mo></math></span>. A graph <em>G</em> is <em>1-embeddable</em> in a surface Σ if <em>G</em> can be drawn in Σ so that every edge of <em>G</em> crosses at most one other edge at a point. R.E.L. Aldred and M.D. Plummer <span><span>[1]</span></span>, <span><span>[2]</span></span> investigated the properties <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> for graphs embedded in the plane, torus, projective plane and Klein bottle. In this paper, we study the property <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> for 1-embeddable graphs in surfaces with small genus. It is shown that no 1-embeddable graph in the plane or projective plane is <span><math><mi>E</mi><mo>(</mo><mn>4</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span> and no 1-embeddable graph in the torus or Klein bottle is <span><math><mi>E</mi><mo>(</mo><mn>5</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span>. As corollaries, no 1-embeddable graph in the plane or projective plane is 5-extendable and no 1-embeddable graph in the torus or Klein bottle is 6-extendable. Some examples show that such results are best possible.</p></div>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On restricted matching extension of 1-embeddable graphs in surfaces with small genus\",\"authors\":\"Jiangyue Zhang, Yan Wu, Heping Zhang\",\"doi\":\"10.1016/j.disc.2024.114172\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Let <em>G</em> be a connected graph with at least <span><math><mn>2</mn><mo>(</mo><mi>m</mi><mo>+</mo><mi>n</mi><mo>+</mo><mn>1</mn><mo>)</mo></math></span> vertices that contains a perfect matching. Then <em>G</em> is <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> if for each pair of disjoint matchings <span><math><mi>M</mi><mo>,</mo><mi>N</mi><mo>⊆</mo><mi>E</mi><mo>(</mo><mi>G</mi><mo>)</mo></math></span> of size <em>m</em> and <em>n</em>, respectively, there exists a perfect matching <em>F</em> in <em>G</em> such that <span><math><mi>M</mi><mo>⊆</mo><mi>F</mi></math></span> and <span><math><mi>F</mi><mo>∩</mo><mi>N</mi><mo>=</mo><mo>∅</mo></math></span>. A graph <em>G</em> is <em>1-embeddable</em> in a surface Σ if <em>G</em> can be drawn in Σ so that every edge of <em>G</em> crosses at most one other edge at a point. R.E.L. Aldred and M.D. Plummer <span><span>[1]</span></span>, <span><span>[2]</span></span> investigated the properties <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> for graphs embedded in the plane, torus, projective plane and Klein bottle. In this paper, we study the property <span><math><mi>E</mi><mo>(</mo><mi>m</mi><mo>,</mo><mi>n</mi><mo>)</mo></math></span> for 1-embeddable graphs in surfaces with small genus. It is shown that no 1-embeddable graph in the plane or projective plane is <span><math><mi>E</mi><mo>(</mo><mn>4</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span> and no 1-embeddable graph in the torus or Klein bottle is <span><math><mi>E</mi><mo>(</mo><mn>5</mn><mo>,</mo><mn>1</mn><mo>)</mo></math></span>. As corollaries, no 1-embeddable graph in the plane or projective plane is 5-extendable and no 1-embeddable graph in the torus or Klein bottle is 6-extendable. Some examples show that such results are best possible.</p></div>\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2024-07-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0012365X24003030\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0012365X24003030","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
On restricted matching extension of 1-embeddable graphs in surfaces with small genus
Let G be a connected graph with at least vertices that contains a perfect matching. Then G is if for each pair of disjoint matchings of size m and n, respectively, there exists a perfect matching F in G such that and . A graph G is 1-embeddable in a surface Σ if G can be drawn in Σ so that every edge of G crosses at most one other edge at a point. R.E.L. Aldred and M.D. Plummer [1], [2] investigated the properties for graphs embedded in the plane, torus, projective plane and Klein bottle. In this paper, we study the property for 1-embeddable graphs in surfaces with small genus. It is shown that no 1-embeddable graph in the plane or projective plane is and no 1-embeddable graph in the torus or Klein bottle is . As corollaries, no 1-embeddable graph in the plane or projective plane is 5-extendable and no 1-embeddable graph in the torus or Klein bottle is 6-extendable. Some examples show that such results are best possible.