{"title":"指数泰勒多项式定义的数域的判别和积分基础","authors":"Ankita Jindal, Sudesh K. Khanduja","doi":"10.1017/s0013091524000105","DOIUrl":null,"url":null,"abstract":"Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" mimetype=\"image\" xlink:href=\"S0013091524000105_inline1.png\" /> <jats:tex-math>$K_n=\\mathbb{Q}(\\alpha_n)$</jats:tex-math> </jats:alternatives> </jats:inline-formula> be a family of algebraic number fields where <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" mimetype=\"image\" xlink:href=\"S0013091524000105_inline2.png\" /> <jats:tex-math>$\\alpha_n\\in \\mathbb{C}$</jats:tex-math> </jats:alternatives> </jats:inline-formula> is a root of the <jats:italic>n</jats:italic>th exponential Taylor polynomial <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" mimetype=\"image\" xlink:href=\"S0013091524000105_inline3.png\" /> <jats:tex-math>$\\frac{x^n}{n!}+ \\frac{x^{n-1}}{(n-1)!}+ \\cdots +\\frac{x^2}{2!}+\\frac{x}{1!}+1$</jats:tex-math> </jats:alternatives> </jats:inline-formula>, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" mimetype=\"image\" xlink:href=\"S0013091524000105_inline4.png\" /> <jats:tex-math>$n\\in \\mathbb{N}$</jats:tex-math> </jats:alternatives> </jats:inline-formula>. In this paper, we give a formula for the exact power of any prime <jats:italic>p</jats:italic> dividing the discriminant of <jats:italic>K<jats:sub>n</jats:sub></jats:italic> in terms of the <jats:italic>p</jats:italic>-adic expansion of <jats:italic>n</jats:italic>. An explicit <jats:italic>p</jats:italic>-integral basis of <jats:italic>K<jats:sub>n</jats:sub></jats:italic> is also given for each prime <jats:italic>p</jats:italic>. These <jats:italic>p</jats:italic>-integral bases quickly lead to the construction of an integral basis of <jats:italic>K<jats:sub>n</jats:sub></jats:italic>.","PeriodicalId":20586,"journal":{"name":"Proceedings of the Edinburgh Mathematical Society","volume":"55 1","pages":""},"PeriodicalIF":0.7000,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Discriminant and integral basis of number fields defined by exponential Taylor polynomials\",\"authors\":\"Ankita Jindal, Sudesh K. Khanduja\",\"doi\":\"10.1017/s0013091524000105\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\\\"http://www.w3.org/1999/xlink\\\" mime-subtype=\\\"png\\\" mimetype=\\\"image\\\" xlink:href=\\\"S0013091524000105_inline1.png\\\" /> <jats:tex-math>$K_n=\\\\mathbb{Q}(\\\\alpha_n)$</jats:tex-math> </jats:alternatives> </jats:inline-formula> be a family of algebraic number fields where <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\\\"http://www.w3.org/1999/xlink\\\" mime-subtype=\\\"png\\\" mimetype=\\\"image\\\" xlink:href=\\\"S0013091524000105_inline2.png\\\" /> <jats:tex-math>$\\\\alpha_n\\\\in \\\\mathbb{C}$</jats:tex-math> </jats:alternatives> </jats:inline-formula> is a root of the <jats:italic>n</jats:italic>th exponential Taylor polynomial <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\\\"http://www.w3.org/1999/xlink\\\" mime-subtype=\\\"png\\\" mimetype=\\\"image\\\" xlink:href=\\\"S0013091524000105_inline3.png\\\" /> <jats:tex-math>$\\\\frac{x^n}{n!}+ \\\\frac{x^{n-1}}{(n-1)!}+ \\\\cdots +\\\\frac{x^2}{2!}+\\\\frac{x}{1!}+1$</jats:tex-math> </jats:alternatives> </jats:inline-formula>, <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\\\"http://www.w3.org/1999/xlink\\\" mime-subtype=\\\"png\\\" mimetype=\\\"image\\\" xlink:href=\\\"S0013091524000105_inline4.png\\\" /> <jats:tex-math>$n\\\\in \\\\mathbb{N}$</jats:tex-math> </jats:alternatives> </jats:inline-formula>. In this paper, we give a formula for the exact power of any prime <jats:italic>p</jats:italic> dividing the discriminant of <jats:italic>K<jats:sub>n</jats:sub></jats:italic> in terms of the <jats:italic>p</jats:italic>-adic expansion of <jats:italic>n</jats:italic>. An explicit <jats:italic>p</jats:italic>-integral basis of <jats:italic>K<jats:sub>n</jats:sub></jats:italic> is also given for each prime <jats:italic>p</jats:italic>. These <jats:italic>p</jats:italic>-integral bases quickly lead to the construction of an integral basis of <jats:italic>K<jats:sub>n</jats:sub></jats:italic>.\",\"PeriodicalId\":20586,\"journal\":{\"name\":\"Proceedings of the Edinburgh Mathematical Society\",\"volume\":\"55 1\",\"pages\":\"\"},\"PeriodicalIF\":0.7000,\"publicationDate\":\"2024-04-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Proceedings of the Edinburgh Mathematical Society\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://doi.org/10.1017/s0013091524000105\",\"RegionNum\":3,\"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":"Proceedings of the Edinburgh Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1017/s0013091524000105","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
摘要
让 $K_n=\mathbb{Q}(\alpha_n)$ 是一个代数数域族,其中 $\alpha_n\in \mathbb{C}$ 是第 n 次指数泰勒多项式 $\frac{x^n}{n!}+ (frac{x^{n-1}}{(n-1)!}+ (cdots +\frac{x^2}{2!}+\frac{x}{1!}+1$ , $n\in \mathbb{N}$。在本文中,我们用 n 的 p-adic 扩展给出了除以 Kn 的判别式的任何素数 p 的精确幂的公式。这些 p 积分基很快就能导致 Kn 积分基的构建。
Discriminant and integral basis of number fields defined by exponential Taylor polynomials
Let $K_n=\mathbb{Q}(\alpha_n)$ be a family of algebraic number fields where $\alpha_n\in \mathbb{C}$ is a root of the nth exponential Taylor polynomial $\frac{x^n}{n!}+ \frac{x^{n-1}}{(n-1)!}+ \cdots +\frac{x^2}{2!}+\frac{x}{1!}+1$, $n\in \mathbb{N}$. In this paper, we give a formula for the exact power of any prime p dividing the discriminant of Kn in terms of the p-adic expansion of n. An explicit p-integral basis of Kn is also given for each prime p. These p-integral bases quickly lead to the construction of an integral basis of Kn.
期刊介绍:
The Edinburgh Mathematical Society was founded in 1883 and over the years, has evolved into the principal society for the promotion of mathematics research in Scotland. The Society has published its Proceedings since 1884. This journal contains research papers on topics in a broad range of pure and applied mathematics, together with a number of topical book reviews.