Katarzyna Kielanowicz, Beata Osińska-Ulrych, Tomasz Rodak, Adam Różycki, Stanisław Spodzieja
{"title":"有效Bertini定理","authors":"Katarzyna Kielanowicz, Beata Osińska-Ulrych, Tomasz Rodak, Adam Różycki, Stanisław Spodzieja","doi":"10.1016/j.bulsci.2025.103648","DOIUrl":null,"url":null,"abstract":"<div><div>The classical Bertini theorem on generic intersection of an algebraic set with hyperplanes says that: <em>Let X be a non-singular closed subvariety of</em> <span><math><msubsup><mrow><mi>P</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span><em>, where</em> <span><math><mi>k</mi></math></span> <em>is an algebraically closed field. Then there exists a hyperplane</em> <span><math><mi>H</mi><mo>⊂</mo><msubsup><mrow><mi>P</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span><em>, not containing X, and such that the scheme</em> <span><math><mi>H</mi><mo>∩</mo><mi>X</mi></math></span> <em>is regular at every point. Furthermore, the set of hyperplanes with this property forms an open dense subset of the complete linear system</em> <span><math><mo>|</mo><mi>H</mi><mo>|</mo></math></span><em>, considered as a projective space.</em> We will show that one can effectively indicate a finite family of hyperplanes <em>H</em>, at least one of which satisfies the assertion of the Bertini theorem, provided that the dimension and degree of the set <em>X</em> are given.</div></div>","PeriodicalId":55313,"journal":{"name":"Bulletin des Sciences Mathematiques","volume":"203 ","pages":"Article 103648"},"PeriodicalIF":1.3000,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effective Bertini theorem\",\"authors\":\"Katarzyna Kielanowicz, Beata Osińska-Ulrych, Tomasz Rodak, Adam Różycki, Stanisław Spodzieja\",\"doi\":\"10.1016/j.bulsci.2025.103648\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The classical Bertini theorem on generic intersection of an algebraic set with hyperplanes says that: <em>Let X be a non-singular closed subvariety of</em> <span><math><msubsup><mrow><mi>P</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span><em>, where</em> <span><math><mi>k</mi></math></span> <em>is an algebraically closed field. Then there exists a hyperplane</em> <span><math><mi>H</mi><mo>⊂</mo><msubsup><mrow><mi>P</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span><em>, not containing X, and such that the scheme</em> <span><math><mi>H</mi><mo>∩</mo><mi>X</mi></math></span> <em>is regular at every point. Furthermore, the set of hyperplanes with this property forms an open dense subset of the complete linear system</em> <span><math><mo>|</mo><mi>H</mi><mo>|</mo></math></span><em>, considered as a projective space.</em> We will show that one can effectively indicate a finite family of hyperplanes <em>H</em>, at least one of which satisfies the assertion of the Bertini theorem, provided that the dimension and degree of the set <em>X</em> are given.</div></div>\",\"PeriodicalId\":55313,\"journal\":{\"name\":\"Bulletin des Sciences Mathematiques\",\"volume\":\"203 \",\"pages\":\"Article 103648\"},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2025-05-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Bulletin des Sciences Mathematiques\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0007449725000740\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin des Sciences Mathematiques","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0007449725000740","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
The classical Bertini theorem on generic intersection of an algebraic set with hyperplanes says that: Let X be a non-singular closed subvariety of, whereis an algebraically closed field. Then there exists a hyperplane, not containing X, and such that the schemeis regular at every point. Furthermore, the set of hyperplanes with this property forms an open dense subset of the complete linear system, considered as a projective space. We will show that one can effectively indicate a finite family of hyperplanes H, at least one of which satisfies the assertion of the Bertini theorem, provided that the dimension and degree of the set X are given.