{"title":"属3 Torelli群的顶部同源群","authors":"Igor A. Spiridonov","doi":"10.1112/topo.12308","DOIUrl":null,"url":null,"abstract":"<p>The Torelli group of a genus <math>\n <semantics>\n <mi>g</mi>\n <annotation>$g$</annotation>\n </semantics></math> oriented surface <math>\n <semantics>\n <msub>\n <mi>Σ</mi>\n <mi>g</mi>\n </msub>\n <annotation>$\\Sigma _g$</annotation>\n </semantics></math> is the subgroup <math>\n <semantics>\n <msub>\n <mi>I</mi>\n <mi>g</mi>\n </msub>\n <annotation>$\\mathcal {I}_g$</annotation>\n </semantics></math> of the mapping class group <math>\n <semantics>\n <mrow>\n <mi>Mod</mi>\n <mo>(</mo>\n <msub>\n <mi>Σ</mi>\n <mi>g</mi>\n </msub>\n <mo>)</mo>\n </mrow>\n <annotation>${\\rm Mod}(\\Sigma _g)$</annotation>\n </semantics></math> consisting of all mapping classes that act trivially on <math>\n <semantics>\n <mrow>\n <msub>\n <mi>H</mi>\n <mn>1</mn>\n </msub>\n <mrow>\n <mo>(</mo>\n <msub>\n <mi>Σ</mi>\n <mi>g</mi>\n </msub>\n <mo>,</mo>\n <mi>Z</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>${\\rm H}_1(\\Sigma _g, \\mathbb {Z})$</annotation>\n </semantics></math>. The quotient group <math>\n <semantics>\n <mrow>\n <mi>Mod</mi>\n <mrow>\n <mo>(</mo>\n <msub>\n <mi>Σ</mi>\n <mi>g</mi>\n </msub>\n <mo>)</mo>\n </mrow>\n <mo>/</mo>\n <msub>\n <mi>I</mi>\n <mi>g</mi>\n </msub>\n </mrow>\n <annotation>${\\rm Mod}(\\Sigma _g) / \\mathcal {I}_g$</annotation>\n </semantics></math> is isomorphic to the symplectic group <math>\n <semantics>\n <mrow>\n <mi>Sp</mi>\n <mo>(</mo>\n <mn>2</mn>\n <mi>g</mi>\n <mo>,</mo>\n <mi>Z</mi>\n <mo>)</mo>\n </mrow>\n <annotation>${\\rm Sp}(2g, \\mathbb {Z})$</annotation>\n </semantics></math>. The cohomological dimension of the group <math>\n <semantics>\n <msub>\n <mi>I</mi>\n <mi>g</mi>\n </msub>\n <annotation>$\\mathcal {I}_g$</annotation>\n </semantics></math> equals to <math>\n <semantics>\n <mrow>\n <mn>3</mn>\n <mi>g</mi>\n <mo>−</mo>\n <mn>5</mn>\n </mrow>\n <annotation>$3g-5$</annotation>\n </semantics></math>. The main goal of the present paper is to compute the top homology group of the Torelli group in the case <math>\n <semantics>\n <mrow>\n <mi>g</mi>\n <mo>=</mo>\n <mn>3</mn>\n </mrow>\n <annotation>$g = 3$</annotation>\n </semantics></math> as <math>\n <semantics>\n <mrow>\n <mi>Sp</mi>\n <mo>(</mo>\n <mn>6</mn>\n <mo>,</mo>\n <mi>Z</mi>\n <mo>)</mo>\n </mrow>\n <annotation>${\\rm Sp}(6, \\mathbb {Z})$</annotation>\n </semantics></math>-module. We prove an isomorphism\n\n </p>","PeriodicalId":56114,"journal":{"name":"Journal of Topology","volume":"16 3","pages":"1048-1092"},"PeriodicalIF":0.8000,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The top homology group of the genus 3 Torelli group\",\"authors\":\"Igor A. Spiridonov\",\"doi\":\"10.1112/topo.12308\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The Torelli group of a genus <math>\\n <semantics>\\n <mi>g</mi>\\n <annotation>$g$</annotation>\\n </semantics></math> oriented surface <math>\\n <semantics>\\n <msub>\\n <mi>Σ</mi>\\n <mi>g</mi>\\n </msub>\\n <annotation>$\\\\Sigma _g$</annotation>\\n </semantics></math> is the subgroup <math>\\n <semantics>\\n <msub>\\n <mi>I</mi>\\n <mi>g</mi>\\n </msub>\\n <annotation>$\\\\mathcal {I}_g$</annotation>\\n </semantics></math> of the mapping class group <math>\\n <semantics>\\n <mrow>\\n <mi>Mod</mi>\\n <mo>(</mo>\\n <msub>\\n <mi>Σ</mi>\\n <mi>g</mi>\\n </msub>\\n <mo>)</mo>\\n </mrow>\\n <annotation>${\\\\rm Mod}(\\\\Sigma _g)$</annotation>\\n </semantics></math> consisting of all mapping classes that act trivially on <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>H</mi>\\n <mn>1</mn>\\n </msub>\\n <mrow>\\n <mo>(</mo>\\n <msub>\\n <mi>Σ</mi>\\n <mi>g</mi>\\n </msub>\\n <mo>,</mo>\\n <mi>Z</mi>\\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation>${\\\\rm H}_1(\\\\Sigma _g, \\\\mathbb {Z})$</annotation>\\n </semantics></math>. The quotient group <math>\\n <semantics>\\n <mrow>\\n <mi>Mod</mi>\\n <mrow>\\n <mo>(</mo>\\n <msub>\\n <mi>Σ</mi>\\n <mi>g</mi>\\n </msub>\\n <mo>)</mo>\\n </mrow>\\n <mo>/</mo>\\n <msub>\\n <mi>I</mi>\\n <mi>g</mi>\\n </msub>\\n </mrow>\\n <annotation>${\\\\rm Mod}(\\\\Sigma _g) / \\\\mathcal {I}_g$</annotation>\\n </semantics></math> is isomorphic to the symplectic group <math>\\n <semantics>\\n <mrow>\\n <mi>Sp</mi>\\n <mo>(</mo>\\n <mn>2</mn>\\n <mi>g</mi>\\n <mo>,</mo>\\n <mi>Z</mi>\\n <mo>)</mo>\\n </mrow>\\n <annotation>${\\\\rm Sp}(2g, \\\\mathbb {Z})$</annotation>\\n </semantics></math>. The cohomological dimension of the group <math>\\n <semantics>\\n <msub>\\n <mi>I</mi>\\n <mi>g</mi>\\n </msub>\\n <annotation>$\\\\mathcal {I}_g$</annotation>\\n </semantics></math> equals to <math>\\n <semantics>\\n <mrow>\\n <mn>3</mn>\\n <mi>g</mi>\\n <mo>−</mo>\\n <mn>5</mn>\\n </mrow>\\n <annotation>$3g-5$</annotation>\\n </semantics></math>. The main goal of the present paper is to compute the top homology group of the Torelli group in the case <math>\\n <semantics>\\n <mrow>\\n <mi>g</mi>\\n <mo>=</mo>\\n <mn>3</mn>\\n </mrow>\\n <annotation>$g = 3$</annotation>\\n </semantics></math> as <math>\\n <semantics>\\n <mrow>\\n <mi>Sp</mi>\\n <mo>(</mo>\\n <mn>6</mn>\\n <mo>,</mo>\\n <mi>Z</mi>\\n <mo>)</mo>\\n </mrow>\\n <annotation>${\\\\rm Sp}(6, \\\\mathbb {Z})$</annotation>\\n </semantics></math>-module. We prove an isomorphism\\n\\n </p>\",\"PeriodicalId\":56114,\"journal\":{\"name\":\"Journal of Topology\",\"volume\":\"16 3\",\"pages\":\"1048-1092\"},\"PeriodicalIF\":0.8000,\"publicationDate\":\"2023-08-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Topology\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1112/topo.12308\",\"RegionNum\":2,\"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 Topology","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1112/topo.12308","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
The top homology group of the genus 3 Torelli group
The Torelli group of a genus oriented surface is the subgroup of the mapping class group consisting of all mapping classes that act trivially on . The quotient group is isomorphic to the symplectic group . The cohomological dimension of the group equals to . The main goal of the present paper is to compute the top homology group of the Torelli group in the case as -module. We prove an isomorphism
期刊介绍:
The Journal of Topology publishes papers of high quality and significance in topology, geometry and adjacent areas of mathematics. Interesting, important and often unexpected links connect topology and geometry with many other parts of mathematics, and the editors welcome submissions on exciting new advances concerning such links, as well as those in the core subject areas of the journal.
The Journal of Topology was founded in 2008. It is published quarterly with articles published individually online prior to appearing in a printed issue.