{"title":"叉子,面条和局表示为n=4","authors":"A. Beridze , P. Traczyk","doi":"10.1016/j.trmi.2018.05.001","DOIUrl":null,"url":null,"abstract":"<div><p>The reduced Burau representation is a natural action of the braid group <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> on the first homology group <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msub><mrow><mo>(</mo><msub><mrow><mover><mrow><mi>D</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>n</mi></mrow></msub><mo>;</mo><mi>Z</mi><mo>)</mo></mrow></math></span> of a suitable infinite cyclic covering space <span><math><msub><mrow><mover><mrow><mi>D</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>n</mi></mrow></msub></math></span> of the <span><math><mi>n</mi></math></span>-punctured disc <span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>. It is known that the Burau representation is faithful for <span><math><mi>n</mi><mo>≤</mo><mn>3</mn></math></span>\nand that it is not faithful for <span><math><mi>n</mi><mo>≥</mo><mn>5</mn></math></span>. We use forks and noodles homological techniques and Bokut–Vesnin generators to analyze the problem for <span><math><mi>n</mi><mo>=</mo><mn>4</mn></math></span>. We present a Conjecture implying faithfulness and a Lemma explaining the implication. We give some arguments suggesting why we expect the Conjecture to be true. Also, we give some geometrically calculated examples and information about data gathered using a C<span>++</span> program.</p></div>","PeriodicalId":43623,"journal":{"name":"Transactions of A Razmadze Mathematical Institute","volume":"172 3","pages":"Pages 337-353"},"PeriodicalIF":0.3000,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.trmi.2018.05.001","citationCount":"6","resultStr":"{\"title\":\"Forks, noodles and the Burau representation for n=4\",\"authors\":\"A. Beridze , P. Traczyk\",\"doi\":\"10.1016/j.trmi.2018.05.001\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The reduced Burau representation is a natural action of the braid group <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span> on the first homology group <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msub><mrow><mo>(</mo><msub><mrow><mover><mrow><mi>D</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>n</mi></mrow></msub><mo>;</mo><mi>Z</mi><mo>)</mo></mrow></math></span> of a suitable infinite cyclic covering space <span><math><msub><mrow><mover><mrow><mi>D</mi></mrow><mrow><mo>̃</mo></mrow></mover></mrow><mrow><mi>n</mi></mrow></msub></math></span> of the <span><math><mi>n</mi></math></span>-punctured disc <span><math><msub><mrow><mi>D</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>. It is known that the Burau representation is faithful for <span><math><mi>n</mi><mo>≤</mo><mn>3</mn></math></span>\\nand that it is not faithful for <span><math><mi>n</mi><mo>≥</mo><mn>5</mn></math></span>. We use forks and noodles homological techniques and Bokut–Vesnin generators to analyze the problem for <span><math><mi>n</mi><mo>=</mo><mn>4</mn></math></span>. We present a Conjecture implying faithfulness and a Lemma explaining the implication. We give some arguments suggesting why we expect the Conjecture to be true. Also, we give some geometrically calculated examples and information about data gathered using a C<span>++</span> program.</p></div>\",\"PeriodicalId\":43623,\"journal\":{\"name\":\"Transactions of A Razmadze Mathematical Institute\",\"volume\":\"172 3\",\"pages\":\"Pages 337-353\"},\"PeriodicalIF\":0.3000,\"publicationDate\":\"2018-12-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.trmi.2018.05.001\",\"citationCount\":\"6\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Transactions of A Razmadze Mathematical Institute\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2346809218300059\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transactions of A Razmadze Mathematical Institute","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2346809218300059","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MATHEMATICS","Score":null,"Total":0}
Forks, noodles and the Burau representation for n=4
The reduced Burau representation is a natural action of the braid group on the first homology group of a suitable infinite cyclic covering space of the -punctured disc . It is known that the Burau representation is faithful for
and that it is not faithful for . We use forks and noodles homological techniques and Bokut–Vesnin generators to analyze the problem for . We present a Conjecture implying faithfulness and a Lemma explaining the implication. We give some arguments suggesting why we expect the Conjecture to be true. Also, we give some geometrically calculated examples and information about data gathered using a C++ program.