{"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":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"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\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2023-08-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1112/topo.12308\",\"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://onlinelibrary.wiley.com/doi/10.1112/topo.12308","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","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