{"title":"论正特征上可容许基群的专门化同构的存在性","authors":"Yu Yang","doi":"10.4310/mrl.2021.v28.n6.a11","DOIUrl":null,"url":null,"abstract":"Let p be a prime number, and let Mg,n be the moduli stack over an algebraic closure Fp of the finite field Fp parameterizing pointed stable curves of type (g, n), Mg,n the open substack of Mg,n parameterizing smooth pointed stable curves, Mg,n the coarse moduli space of Mg,n, Mg,n the coarse moduli space of Mg,n, q ∈ Mg,n an arbitrary point, and Πq the admissible fundamental group of a pointed stable curve corresponding to a geometric point over q. In the present paper, we prove that, there exists q1, q2 ∈ Mg,n \\ Mg,n such that q1 is a specialization of q2, that q1 ̸= q2, and that a specialization homomorphism sp : Πq2 ↠ Πq1 is an isomorphism.","PeriodicalId":49857,"journal":{"name":"Mathematical Research Letters","volume":"15 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":"{\"title\":\"On the existence of specialization isomorphisms of admissible fundamental groups in positive characteristic\",\"authors\":\"Yu Yang\",\"doi\":\"10.4310/mrl.2021.v28.n6.a11\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let p be a prime number, and let Mg,n be the moduli stack over an algebraic closure Fp of the finite field Fp parameterizing pointed stable curves of type (g, n), Mg,n the open substack of Mg,n parameterizing smooth pointed stable curves, Mg,n the coarse moduli space of Mg,n, Mg,n the coarse moduli space of Mg,n, q ∈ Mg,n an arbitrary point, and Πq the admissible fundamental group of a pointed stable curve corresponding to a geometric point over q. In the present paper, we prove that, there exists q1, q2 ∈ Mg,n \\\\ Mg,n such that q1 is a specialization of q2, that q1 ̸= q2, and that a specialization homomorphism sp : Πq2 ↠ Πq1 is an isomorphism.\",\"PeriodicalId\":49857,\"journal\":{\"name\":\"Mathematical Research Letters\",\"volume\":\"15 1\",\"pages\":\"\"},\"PeriodicalIF\":0.6000,\"publicationDate\":\"2021-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"4\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Mathematical Research Letters\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.4310/mrl.2021.v28.n6.a11\",\"RegionNum\":3,\"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":"Mathematical Research Letters","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.4310/mrl.2021.v28.n6.a11","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
On the existence of specialization isomorphisms of admissible fundamental groups in positive characteristic
Let p be a prime number, and let Mg,n be the moduli stack over an algebraic closure Fp of the finite field Fp parameterizing pointed stable curves of type (g, n), Mg,n the open substack of Mg,n parameterizing smooth pointed stable curves, Mg,n the coarse moduli space of Mg,n, Mg,n the coarse moduli space of Mg,n, q ∈ Mg,n an arbitrary point, and Πq the admissible fundamental group of a pointed stable curve corresponding to a geometric point over q. In the present paper, we prove that, there exists q1, q2 ∈ Mg,n \ Mg,n such that q1 is a specialization of q2, that q1 ̸= q2, and that a specialization homomorphism sp : Πq2 ↠ Πq1 is an isomorphism.
期刊介绍:
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