{"title":"Hopf代数的一个指标公式 $$k^{S_{n-1}}\\#kC_n$$","authors":"Kayla Orlinsky","doi":"10.1007/s10468-023-10230-0","DOIUrl":null,"url":null,"abstract":"<div><p>The semisimple bismash product Hopf algebra <span>\\(J_n=k^{S_{n-1}}\\#kC_n\\)</span> for an algebraically closed field <i>k</i> is constructed using the matched pair actions of <span>\\(C_n\\)</span> and <span>\\(S_{n-1}\\)</span> on each other. In this work, we reinterpret these actions and use an understanding of the involutions of <span>\\(S_{n-1}\\)</span> to derive a new Froebnius-Schur indicator formula for irreps of <span>\\(J_n\\)</span> and show that for <i>n</i> odd, all indicators of <span>\\(J_n\\)</span> are nonnegative. We also derive a variety of counting formulas including Theorem 6.2.2 which fully describes the indicators of all 2-dimensional irreps of <span>\\(J_n\\)</span> and Theorem 6.1.2 which fully describes the indicators of all odd-dimensional irreps of <span>\\(J_n\\)</span> and use these formulas to show that nonzero indicators become rare for large <i>n</i>.</p></div>","PeriodicalId":50825,"journal":{"name":"Algebras and Representation Theory","volume":"27 1","pages":"495 - 545"},"PeriodicalIF":0.5000,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10468-023-10230-0.pdf","citationCount":"0","resultStr":"{\"title\":\"An Indicator Formula for the Hopf Algebra \\\\(k^{S_{n-1}}\\\\#kC_n\\\\)\",\"authors\":\"Kayla Orlinsky\",\"doi\":\"10.1007/s10468-023-10230-0\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The semisimple bismash product Hopf algebra <span>\\\\(J_n=k^{S_{n-1}}\\\\#kC_n\\\\)</span> for an algebraically closed field <i>k</i> is constructed using the matched pair actions of <span>\\\\(C_n\\\\)</span> and <span>\\\\(S_{n-1}\\\\)</span> on each other. In this work, we reinterpret these actions and use an understanding of the involutions of <span>\\\\(S_{n-1}\\\\)</span> to derive a new Froebnius-Schur indicator formula for irreps of <span>\\\\(J_n\\\\)</span> and show that for <i>n</i> odd, all indicators of <span>\\\\(J_n\\\\)</span> are nonnegative. We also derive a variety of counting formulas including Theorem 6.2.2 which fully describes the indicators of all 2-dimensional irreps of <span>\\\\(J_n\\\\)</span> and Theorem 6.1.2 which fully describes the indicators of all odd-dimensional irreps of <span>\\\\(J_n\\\\)</span> and use these formulas to show that nonzero indicators become rare for large <i>n</i>.</p></div>\",\"PeriodicalId\":50825,\"journal\":{\"name\":\"Algebras and Representation Theory\",\"volume\":\"27 1\",\"pages\":\"495 - 545\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2023-09-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s10468-023-10230-0.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Algebras and Representation Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s10468-023-10230-0\",\"RegionNum\":4,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algebras and Representation Theory","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s10468-023-10230-0","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
An Indicator Formula for the Hopf Algebra \(k^{S_{n-1}}\#kC_n\)
The semisimple bismash product Hopf algebra \(J_n=k^{S_{n-1}}\#kC_n\) for an algebraically closed field k is constructed using the matched pair actions of \(C_n\) and \(S_{n-1}\) on each other. In this work, we reinterpret these actions and use an understanding of the involutions of \(S_{n-1}\) to derive a new Froebnius-Schur indicator formula for irreps of \(J_n\) and show that for n odd, all indicators of \(J_n\) are nonnegative. We also derive a variety of counting formulas including Theorem 6.2.2 which fully describes the indicators of all 2-dimensional irreps of \(J_n\) and Theorem 6.1.2 which fully describes the indicators of all odd-dimensional irreps of \(J_n\) and use these formulas to show that nonzero indicators become rare for large n.
期刊介绍:
Algebras and Representation Theory features carefully refereed papers relating, in its broadest sense, to the structure and representation theory of algebras, including Lie algebras and superalgebras, rings of differential operators, group rings and algebras, C*-algebras and Hopf algebras, with particular emphasis on quantum groups.
The journal contains high level, significant and original research papers, as well as expository survey papers written by specialists who present the state-of-the-art of well-defined subjects or subdomains. Occasionally, special issues on specific subjects are published as well, the latter allowing specialists and non-specialists to quickly get acquainted with new developments and topics within the field of rings, algebras and their applications.