{"title":"格拉斯曼之间的变形,II","authors":"Gianluca Occhetta, Eugenia Tondelli","doi":"10.1007/s00013-024-01986-y","DOIUrl":null,"url":null,"abstract":"<div><p>Denote by <span>\\({\\mathbb {G}}(k,n)\\)</span> the Grassmannian of linear subspaces of dimension <i>k</i> in <span>\\({\\mathbb {P}}^n\\)</span>. We show that if <span>\\(\\varphi :{\\mathbb {G}}(l,n) \\rightarrow {\\mathbb {G}}(k,n)\\)</span> is a nonconstant morphism and <span>\\(l \\not =0,n-1\\)</span>, then <span>\\(l=k\\)</span> or <span>\\(l=n-k-1\\)</span> and <span>\\(\\varphi \\)</span> is an isomorphism.</p></div>","PeriodicalId":8346,"journal":{"name":"Archiv der Mathematik","volume":null,"pages":null},"PeriodicalIF":0.5000,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00013-024-01986-y.pdf","citationCount":"0","resultStr":"{\"title\":\"Morphisms between Grassmannians, II\",\"authors\":\"Gianluca Occhetta, Eugenia Tondelli\",\"doi\":\"10.1007/s00013-024-01986-y\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Denote by <span>\\\\({\\\\mathbb {G}}(k,n)\\\\)</span> the Grassmannian of linear subspaces of dimension <i>k</i> in <span>\\\\({\\\\mathbb {P}}^n\\\\)</span>. We show that if <span>\\\\(\\\\varphi :{\\\\mathbb {G}}(l,n) \\\\rightarrow {\\\\mathbb {G}}(k,n)\\\\)</span> is a nonconstant morphism and <span>\\\\(l \\\\not =0,n-1\\\\)</span>, then <span>\\\\(l=k\\\\)</span> or <span>\\\\(l=n-k-1\\\\)</span> and <span>\\\\(\\\\varphi \\\\)</span> is an isomorphism.</p></div>\",\"PeriodicalId\":8346,\"journal\":{\"name\":\"Archiv der Mathematik\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2024-03-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://link.springer.com/content/pdf/10.1007/s00013-024-01986-y.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Archiv der Mathematik\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s00013-024-01986-y\",\"RegionNum\":4,\"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":"Archiv der Mathematik","FirstCategoryId":"100","ListUrlMain":"https://link.springer.com/article/10.1007/s00013-024-01986-y","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
Abstract Denote by \({\mathbb {G}}(k,n)\) the Grassmannian of linear subspaces of dimension k in \({\mathbb {P}}^n\) .我们证明如果 \(\varphi :{\mathbb {G}}(l,n) \rightarrow {\mathbb {G}}(k,n)\) 是一个非恒定变形并且 \(l \not =0,n-1\) ,那么 \(l=k\) 或者 \(l=n-k-1\) 和 \(\varphi\) 是一个同构。
Denote by \({\mathbb {G}}(k,n)\) the Grassmannian of linear subspaces of dimension k in \({\mathbb {P}}^n\). We show that if \(\varphi :{\mathbb {G}}(l,n) \rightarrow {\mathbb {G}}(k,n)\) is a nonconstant morphism and \(l \not =0,n-1\), then \(l=k\) or \(l=n-k-1\) and \(\varphi \) is an isomorphism.
期刊介绍:
Archiv der Mathematik (AdM) publishes short high quality research papers in every area of mathematics which are not overly technical in nature and addressed to a broad readership.