{"title":"函数域上二次形式各向同性的局部-全局原理失效","authors":"Asher Auel, V. Suresh","doi":"10.2140/ant.2024.18.1497","DOIUrl":null,"url":null,"abstract":"<p>We prove the failure of the local-global principle, with respect to discrete valuations, for isotropy of quadratic forms in <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mrow><mn>2</mn></mrow><mrow><mi>n</mi></mrow></msup></math> variables over function fields of transcendence degree <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>n</mi>\n<mo>≥</mo> <mn>2</mn></math> over an algebraically closed field of characteristic <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mo>≠</mo><mn>2</mn></math>. Our construction involves the generalized Kummer varieties considered by Borcea and by Cynk and Hulek as well as new results on the nontriviality of unramified cohomology of products of elliptic curves over discretely valued fields. </p>","PeriodicalId":50828,"journal":{"name":"Algebra & Number Theory","volume":"8 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Failure of the local-global principle for isotropy of quadratic forms over function fields\",\"authors\":\"Asher Auel, V. Suresh\",\"doi\":\"10.2140/ant.2024.18.1497\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We prove the failure of the local-global principle, with respect to discrete valuations, for isotropy of quadratic forms in <math display=\\\"inline\\\" xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msup><mrow><mn>2</mn></mrow><mrow><mi>n</mi></mrow></msup></math> variables over function fields of transcendence degree <math display=\\\"inline\\\" xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mi>n</mi>\\n<mo>≥</mo> <mn>2</mn></math> over an algebraically closed field of characteristic <math display=\\\"inline\\\" xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mo>≠</mo><mn>2</mn></math>. Our construction involves the generalized Kummer varieties considered by Borcea and by Cynk and Hulek as well as new results on the nontriviality of unramified cohomology of products of elliptic curves over discretely valued fields. </p>\",\"PeriodicalId\":50828,\"journal\":{\"name\":\"Algebra & Number Theory\",\"volume\":\"8 1\",\"pages\":\"\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2024-09-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Algebra & Number Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.2140/ant.2024.18.1497\",\"RegionNum\":1,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Algebra & Number Theory","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.2140/ant.2024.18.1497","RegionNum":1,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Failure of the local-global principle for isotropy of quadratic forms over function fields
We prove the failure of the local-global principle, with respect to discrete valuations, for isotropy of quadratic forms in variables over function fields of transcendence degree over an algebraically closed field of characteristic . Our construction involves the generalized Kummer varieties considered by Borcea and by Cynk and Hulek as well as new results on the nontriviality of unramified cohomology of products of elliptic curves over discretely valued fields.
期刊介绍:
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