{"title":"德林菲尔德曲线的典型表示","authors":"Lucas Laurent, Bernhard Köck","doi":"10.1002/mana.202200402","DOIUrl":null,"url":null,"abstract":"<p>If <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math> is a smooth projective curve over an algebraically closed field <span></span><math>\n <semantics>\n <mi>F</mi>\n <annotation>$\\mathbb {F}$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mi>G</mi>\n <annotation>$G$</annotation>\n </semantics></math> is a group of automorphisms of <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math>, the <i>canonical representation of</i> <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math> is given by the induced <span></span><math>\n <semantics>\n <mi>F</mi>\n <annotation>$\\mathbb {F}$</annotation>\n </semantics></math>-linear action of <span></span><math>\n <semantics>\n <mi>G</mi>\n <annotation>$G$</annotation>\n </semantics></math> on the vector space <span></span><math>\n <semantics>\n <mrow>\n <msup>\n <mi>H</mi>\n <mn>0</mn>\n </msup>\n <mfenced>\n <mi>C</mi>\n <mo>,</mo>\n <msub>\n <mi>Ω</mi>\n <mi>C</mi>\n </msub>\n </mfenced>\n </mrow>\n <annotation>$H^0\\left(C,\\Omega _C\\right)$</annotation>\n </semantics></math> of holomorphic differentials on <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math>. Computing it is still an open problem in general when the cover <span></span><math>\n <semantics>\n <mrow>\n <mi>C</mi>\n <mo>→</mo>\n <mi>C</mi>\n <mo>/</mo>\n <mi>G</mi>\n </mrow>\n <annotation>$C \\rightarrow C/G$</annotation>\n </semantics></math> is wildly ramified. In this paper, we fix a prime power <span></span><math>\n <semantics>\n <mi>q</mi>\n <annotation>$q$</annotation>\n </semantics></math>, we consider the Drinfeld curve, that is, the curve <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math> given by the equation <span></span><math>\n <semantics>\n <mrow>\n <mi>X</mi>\n <msup>\n <mi>Y</mi>\n <mi>q</mi>\n </msup>\n <mo>−</mo>\n <msup>\n <mi>X</mi>\n <mi>q</mi>\n </msup>\n <mi>Y</mi>\n <mo>−</mo>\n <msup>\n <mi>Z</mi>\n <mrow>\n <mi>q</mi>\n <mo>+</mo>\n <mn>1</mn>\n </mrow>\n </msup>\n <mo>=</mo>\n <mn>0</mn>\n </mrow>\n <annotation>${XY^q-X^qY-Z^{q+1}=0}$</annotation>\n </semantics></math> over <span></span><math>\n <semantics>\n <mrow>\n <mi>F</mi>\n <mo>=</mo>\n <mspace></mspace>\n <mover>\n <msub>\n <mi>F</mi>\n <mi>q</mi>\n </msub>\n <mo>¯</mo>\n </mover>\n <mspace></mspace>\n </mrow>\n <annotation>$\\mathbb {F}=\\hspace{0.83328pt}\\overline{\\hspace{-0.83328pt}\\mathbb {F}_q\\hspace{-0.83328pt}}\\hspace{0.83328pt}$</annotation>\n </semantics></math> together with its standard action by <span></span><math>\n <semantics>\n <mrow>\n <mi>G</mi>\n <mo>=</mo>\n <mi>S</mi>\n <msub>\n <mi>L</mi>\n <mn>2</mn>\n </msub>\n <mfenced>\n <msub>\n <mi>F</mi>\n <mi>q</mi>\n </msub>\n </mfenced>\n </mrow>\n <annotation>${G=SL_2\\left(\\mathbb {F}_q\\right)}$</annotation>\n </semantics></math>, and decompose <span></span><math>\n <semantics>\n <mrow>\n <msup>\n <mi>H</mi>\n <mn>0</mn>\n </msup>\n <mfenced>\n <mi>C</mi>\n <mo>,</mo>\n <msub>\n <mi>Ω</mi>\n <mi>C</mi>\n </msub>\n </mfenced>\n </mrow>\n <annotation>$H^0\\left(C,\\Omega _C\\right)$</annotation>\n </semantics></math> as a direct sum of indecomposable representations of <span></span><math>\n <semantics>\n <mi>G</mi>\n <annotation>$G$</annotation>\n </semantics></math>, thus solving the aforementioned problem in this case.</p>","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mana.202200402","citationCount":"0","resultStr":"{\"title\":\"The canonical representation of the Drinfeld curve\",\"authors\":\"Lucas Laurent, Bernhard Köck\",\"doi\":\"10.1002/mana.202200402\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>If <span></span><math>\\n <semantics>\\n <mi>C</mi>\\n <annotation>$C$</annotation>\\n </semantics></math> is a smooth projective curve over an algebraically closed field <span></span><math>\\n <semantics>\\n <mi>F</mi>\\n <annotation>$\\\\mathbb {F}$</annotation>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mi>G</mi>\\n <annotation>$G$</annotation>\\n </semantics></math> is a group of automorphisms of <span></span><math>\\n <semantics>\\n <mi>C</mi>\\n <annotation>$C$</annotation>\\n </semantics></math>, the <i>canonical representation of</i> <span></span><math>\\n <semantics>\\n <mi>C</mi>\\n <annotation>$C$</annotation>\\n </semantics></math> is given by the induced <span></span><math>\\n <semantics>\\n <mi>F</mi>\\n <annotation>$\\\\mathbb {F}$</annotation>\\n </semantics></math>-linear action of <span></span><math>\\n <semantics>\\n <mi>G</mi>\\n <annotation>$G$</annotation>\\n </semantics></math> on the vector space <span></span><math>\\n <semantics>\\n <mrow>\\n <msup>\\n <mi>H</mi>\\n <mn>0</mn>\\n </msup>\\n <mfenced>\\n <mi>C</mi>\\n <mo>,</mo>\\n <msub>\\n <mi>Ω</mi>\\n <mi>C</mi>\\n </msub>\\n </mfenced>\\n </mrow>\\n <annotation>$H^0\\\\left(C,\\\\Omega _C\\\\right)$</annotation>\\n </semantics></math> of holomorphic differentials on <span></span><math>\\n <semantics>\\n <mi>C</mi>\\n <annotation>$C$</annotation>\\n </semantics></math>. Computing it is still an open problem in general when the cover <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>C</mi>\\n <mo>→</mo>\\n <mi>C</mi>\\n <mo>/</mo>\\n <mi>G</mi>\\n </mrow>\\n <annotation>$C \\\\rightarrow C/G$</annotation>\\n </semantics></math> is wildly ramified. In this paper, we fix a prime power <span></span><math>\\n <semantics>\\n <mi>q</mi>\\n <annotation>$q$</annotation>\\n </semantics></math>, we consider the Drinfeld curve, that is, the curve <span></span><math>\\n <semantics>\\n <mi>C</mi>\\n <annotation>$C$</annotation>\\n </semantics></math> given by the equation <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>X</mi>\\n <msup>\\n <mi>Y</mi>\\n <mi>q</mi>\\n </msup>\\n <mo>−</mo>\\n <msup>\\n <mi>X</mi>\\n <mi>q</mi>\\n </msup>\\n <mi>Y</mi>\\n <mo>−</mo>\\n <msup>\\n <mi>Z</mi>\\n <mrow>\\n <mi>q</mi>\\n <mo>+</mo>\\n <mn>1</mn>\\n </mrow>\\n </msup>\\n <mo>=</mo>\\n <mn>0</mn>\\n </mrow>\\n <annotation>${XY^q-X^qY-Z^{q+1}=0}$</annotation>\\n </semantics></math> over <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>F</mi>\\n <mo>=</mo>\\n <mspace></mspace>\\n <mover>\\n <msub>\\n <mi>F</mi>\\n <mi>q</mi>\\n </msub>\\n <mo>¯</mo>\\n </mover>\\n <mspace></mspace>\\n </mrow>\\n <annotation>$\\\\mathbb {F}=\\\\hspace{0.83328pt}\\\\overline{\\\\hspace{-0.83328pt}\\\\mathbb {F}_q\\\\hspace{-0.83328pt}}\\\\hspace{0.83328pt}$</annotation>\\n </semantics></math> together with its standard action by <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>G</mi>\\n <mo>=</mo>\\n <mi>S</mi>\\n <msub>\\n <mi>L</mi>\\n <mn>2</mn>\\n </msub>\\n <mfenced>\\n <msub>\\n <mi>F</mi>\\n <mi>q</mi>\\n </msub>\\n </mfenced>\\n </mrow>\\n <annotation>${G=SL_2\\\\left(\\\\mathbb {F}_q\\\\right)}$</annotation>\\n </semantics></math>, and decompose <span></span><math>\\n <semantics>\\n <mrow>\\n <msup>\\n <mi>H</mi>\\n <mn>0</mn>\\n </msup>\\n <mfenced>\\n <mi>C</mi>\\n <mo>,</mo>\\n <msub>\\n <mi>Ω</mi>\\n <mi>C</mi>\\n </msub>\\n </mfenced>\\n </mrow>\\n <annotation>$H^0\\\\left(C,\\\\Omega _C\\\\right)$</annotation>\\n </semantics></math> as a direct sum of indecomposable representations of <span></span><math>\\n <semantics>\\n <mi>G</mi>\\n <annotation>$G$</annotation>\\n </semantics></math>, thus solving the aforementioned problem in this case.</p>\",\"PeriodicalId\":0,\"journal\":{\"name\":\"\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0,\"publicationDate\":\"2024-09-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mana.202200402\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/mana.202200402\",\"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://onlinelibrary.wiley.com/doi/10.1002/mana.202200402","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
如果 是一条代数闭域上的光滑投影曲线,并且 是 的自动形群 ,那么 的典型表示是由 的在全形微分向量空间上的诱导线性作用给出的。在一般情况下,当覆盖有大量斜边时,计算它仍是一个未决问题。在本文中,我们固定一个质幂 ,考虑德林费尔德曲线,即由方程 over 及其标准作用给出的曲线,并将其分解为Ⅳ的不可分解表示的直接和,从而解决了这种情况下的上述问题。
The canonical representation of the Drinfeld curve
If is a smooth projective curve over an algebraically closed field and is a group of automorphisms of , the canonical representation of is given by the induced -linear action of on the vector space of holomorphic differentials on . Computing it is still an open problem in general when the cover is wildly ramified. In this paper, we fix a prime power , we consider the Drinfeld curve, that is, the curve given by the equation over together with its standard action by , and decompose as a direct sum of indecomposable representations of , thus solving the aforementioned problem in this case.