{"title":"p-groups, p-rank, and semistable reduction of coverings of curves","authors":"Yu Yang","doi":"10.2140/ant.2024.18.281","DOIUrl":null,"url":null,"abstract":"<p>We prove various explicit formulas concerning <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-rank of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-coverings of pointed semistable curves over discrete valuation rings. In particular, we obtain a full generalization of Raynaud’s formula for <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-rank of fibers over <span>nonmarked smooth </span>closed points in the case of <span>arbitrary </span>closed points. As an application, for abelian <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-coverings, we give an affirmative answer to an open problem concerning boundedness of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>p</mi></math>-rank asked by Saïdi more than twenty years ago. </p>","PeriodicalId":50828,"journal":{"name":"Algebra & Number Theory","volume":"5 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algebra & Number Theory","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.2140/ant.2024.18.281","RegionNum":1,"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 prove various explicit formulas concerning -rank of -coverings of pointed semistable curves over discrete valuation rings. In particular, we obtain a full generalization of Raynaud’s formula for -rank of fibers over nonmarked smooth closed points in the case of arbitrary closed points. As an application, for abelian -coverings, we give an affirmative answer to an open problem concerning boundedness of -rank asked by Saïdi more than twenty years ago.
期刊介绍:
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