{"title":"On the finiteness of maps into simple abelian varieties satisfying certain tangency conditions","authors":"Finn Bartsch","doi":"10.1112/blms.70119","DOIUrl":null,"url":null,"abstract":"<p>We show that given a simple abelian variety <span></span><math>\n <semantics>\n <mi>A</mi>\n <annotation>$A$</annotation>\n </semantics></math> and a normal variety <span></span><math>\n <semantics>\n <mi>V</mi>\n <annotation>$V$</annotation>\n </semantics></math> defined over a finitely generated field <span></span><math>\n <semantics>\n <mi>K</mi>\n <annotation>$K$</annotation>\n </semantics></math> of characteristic zero, the set of non-constant morphisms <span></span><math>\n <semantics>\n <mrow>\n <mi>V</mi>\n <mo>→</mo>\n <mi>A</mi>\n </mrow>\n <annotation>$V \\rightarrow A$</annotation>\n </semantics></math> satisfying certain tangency conditions imposed by a Campana orbifold divisor <span></span><math>\n <semantics>\n <mi>Δ</mi>\n <annotation>$\\Delta$</annotation>\n </semantics></math> on <span></span><math>\n <semantics>\n <mi>A</mi>\n <annotation>$A$</annotation>\n </semantics></math> is finite. To do so, we study the geometry of the scheme <span></span><math>\n <semantics>\n <mrow>\n <msup>\n <munder>\n <mo>Hom</mo>\n <mo>̲</mo>\n </munder>\n <mo>nc</mo>\n </msup>\n <mrow>\n <mo>(</mo>\n <mi>C</mi>\n <mo>,</mo>\n <mrow>\n <mo>(</mo>\n <mi>A</mi>\n <mo>,</mo>\n <mi>Δ</mi>\n <mo>)</mo>\n </mrow>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$\\underline{\\operatorname{Hom}}^{\\operatorname{nc}}(C, (A, \\Delta))$</annotation>\n </semantics></math> parameterizing such morphisms from a smooth curve <span></span><math>\n <semantics>\n <mi>C</mi>\n <annotation>$C$</annotation>\n </semantics></math> and show that it admits a quasi-finite non-dominant morphism to <span></span><math>\n <semantics>\n <mi>A</mi>\n <annotation>$A$</annotation>\n </semantics></math>.</p>","PeriodicalId":55298,"journal":{"name":"Bulletin of the London Mathematical Society","volume":"57 9","pages":"2723-2730"},"PeriodicalIF":0.9000,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://londmathsoc.onlinelibrary.wiley.com/doi/epdf/10.1112/blms.70119","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the London Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/blms.70119","RegionNum":3,"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 show that given a simple abelian variety and a normal variety defined over a finitely generated field of characteristic zero, the set of non-constant morphisms satisfying certain tangency conditions imposed by a Campana orbifold divisor on is finite. To do so, we study the geometry of the scheme parameterizing such morphisms from a smooth curve and show that it admits a quasi-finite non-dominant morphism to .