{"title":"The tame Nori fundamental group","authors":"Indranil Biswas , Manish Kumar , A.J. Parameswaran","doi":"10.1016/j.jalgebra.2025.06.006","DOIUrl":null,"url":null,"abstract":"<div><div>We introduce three notion of tameness of the Nori fundamental group scheme for a normal quasiprojective variety <em>X</em> over an algebraically closed field. It is proved that these three notions agree if <em>X</em> admits a smooth completion with strict normal crossing divisor as the complement. We also prove a Lefschetz type restriction theorem for the tame Nori fundamental group scheme for such an <em>X</em>.</div></div>","PeriodicalId":14888,"journal":{"name":"Journal of Algebra","volume":"682 ","pages":"Pages 315-330"},"PeriodicalIF":0.8000,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Algebra","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0021869325003503","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
We introduce three notion of tameness of the Nori fundamental group scheme for a normal quasiprojective variety X over an algebraically closed field. It is proved that these three notions agree if X admits a smooth completion with strict normal crossing divisor as the complement. We also prove a Lefschetz type restriction theorem for the tame Nori fundamental group scheme for such an X.
期刊介绍:
The Journal of Algebra is a leading international journal and publishes papers that demonstrate high quality research results in algebra and related computational aspects. Only the very best and most interesting papers are to be considered for publication in the journal. With this in mind, it is important that the contribution offer a substantial result that will have a lasting effect upon the field. The journal also seeks work that presents innovative techniques that offer promising results for future research.