{"title":"p-ADIC 曲线算术基本群的局部段","authors":"MOHAMED SAÏDI","doi":"10.1017/nmj.2023.33","DOIUrl":null,"url":null,"abstract":"<p>We investigate <span>sections</span> of the arithmetic fundamental group <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline1.png\"><span data-mathjax-type=\"texmath\"><span>$\\pi _1(X)$</span></span></img></span></span> where <span>X</span> is either a <span>smooth affinoid p-adic curve</span>, or a <span>formal germ of a p-adic curve</span>, and prove that they can be lifted (unconditionally) to sections of cuspidally abelian Galois groups. As a consequence, if <span>X</span> admits a compactification <span>Y</span>, and the exact sequence of <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline2.png\"><span data-mathjax-type=\"texmath\"><span>$\\pi _1(X)$</span></span></img></span></span> <span>splits</span>, then <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline3.png\"><span data-mathjax-type=\"texmath\"><span>$\\text {index} (Y)=1$</span></span></img></span></span>. We also exhibit a necessary and sufficient condition for a section of <span><span><img data-mimesubtype=\"png\" data-type=\"\" src=\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline4.png\"><span data-mathjax-type=\"texmath\"><span>$\\pi _1(X)$</span></span></img></span></span> to arise from a <span>rational point</span> of <span>Y</span>. One of the key ingredients in our investigation is the fact, we prove in this paper in case <span>X</span> is affinoid, that the Picard group of <span>X</span> is <span>finite</span>.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"LOCAL SECTIONS OF ARITHMETIC FUNDAMENTAL GROUPS OF p-ADIC CURVES\",\"authors\":\"MOHAMED SAÏDI\",\"doi\":\"10.1017/nmj.2023.33\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We investigate <span>sections</span> of the arithmetic fundamental group <span><span><img data-mimesubtype=\\\"png\\\" data-type=\\\"\\\" src=\\\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline1.png\\\"><span data-mathjax-type=\\\"texmath\\\"><span>$\\\\pi _1(X)$</span></span></img></span></span> where <span>X</span> is either a <span>smooth affinoid p-adic curve</span>, or a <span>formal germ of a p-adic curve</span>, and prove that they can be lifted (unconditionally) to sections of cuspidally abelian Galois groups. As a consequence, if <span>X</span> admits a compactification <span>Y</span>, and the exact sequence of <span><span><img data-mimesubtype=\\\"png\\\" data-type=\\\"\\\" src=\\\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline2.png\\\"><span data-mathjax-type=\\\"texmath\\\"><span>$\\\\pi _1(X)$</span></span></img></span></span> <span>splits</span>, then <span><span><img data-mimesubtype=\\\"png\\\" data-type=\\\"\\\" src=\\\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline3.png\\\"><span data-mathjax-type=\\\"texmath\\\"><span>$\\\\text {index} (Y)=1$</span></span></img></span></span>. We also exhibit a necessary and sufficient condition for a section of <span><span><img data-mimesubtype=\\\"png\\\" data-type=\\\"\\\" src=\\\"https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary:20231219130139179-0193:S0027763023000338:S0027763023000338_inline4.png\\\"><span data-mathjax-type=\\\"texmath\\\"><span>$\\\\pi _1(X)$</span></span></img></span></span> to arise from a <span>rational point</span> of <span>Y</span>. One of the key ingredients in our investigation is the fact, we prove in this paper in case <span>X</span> is affinoid, that the Picard group of <span>X</span> is <span>finite</span>.</p>\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2023-12-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1017/nmj.2023.33\",\"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://doi.org/10.1017/nmj.2023.33","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
我们研究了算术基本群 $\pi _1(X)$的截面,其中 X 是光滑的affinoid p-adic曲线,或者是 p-adic曲线的形式胚芽,并证明它们可以(无条件地)提升到簕杜鹃无边际伽罗瓦群的截面。因此,如果 X 允许一个紧凑化 Y,并且 $\pi _1(X)$ 的精确序列分裂,那么 $text {index} (Y)=1$ 。我们还展示了 $\pi _1(X)$ 的一个部分从 Y 的一个有理点产生的必要条件和充分条件。我们研究的一个关键因素是,我们在本文中证明了在 X 是affinoid的情况下,X 的 Picard 群是有限的。
LOCAL SECTIONS OF ARITHMETIC FUNDAMENTAL GROUPS OF p-ADIC CURVES
We investigate sections of the arithmetic fundamental group $\pi _1(X)$ where X is either a smooth affinoid p-adic curve, or a formal germ of a p-adic curve, and prove that they can be lifted (unconditionally) to sections of cuspidally abelian Galois groups. As a consequence, if X admits a compactification Y, and the exact sequence of $\pi _1(X)$splits, then $\text {index} (Y)=1$. We also exhibit a necessary and sufficient condition for a section of $\pi _1(X)$ to arise from a rational point of Y. One of the key ingredients in our investigation is the fact, we prove in this paper in case X is affinoid, that the Picard group of X is finite.