{ "id": "1508.07624", "version": "v1", "published": "2015-08-30T19:37:22.000Z", "updated": "2015-08-30T19:37:22.000Z", "title": "Some finiteness results on monogenic orders in positive characteristic", "authors": [ "Jason P. Bell", "Khoa D. Nguyen" ], "comment": "27 pages, comments are welcome", "categories": [ "math.NT" ], "abstract": "This work is motivated by the papers [EG85] and [Ngu15] in which the following two problems are solved. Let $\\mathcal{O}$ is a finitely generated $\\mathbb{Z}$-algebra that is an integrally closed domain of characteristic zero, consider the following problems: (A) Fix $s$ that is integral over $\\mathcal{O}$, describe all $t$ such that $\\mathcal{O}[s]=\\mathcal{O}[t]$. (B) Fix $s$ and $t$ that are integral over $\\mathcal{O}$, describe all pairs $(m,n)\\in\\mathbb{N}^2$ such that $\\mathcal{O}[s^m]=\\mathcal{O}[t^n]$. In this paper, we solve these problems and provide a uniform bound for a certain \"discriminant form equation\" that is closely related to Problem (A) when $\\mathcal{O}$ has characteristic $p>0$. While our general strategy roughly follows [EG85] and [Ngu15], many new delicate issues arise due to the presence of the Frobenius automorphisms $x\\mapsto x^p$. Recent advances in unit equations over fields of positive characteristic together with classical results in characteristic zero play an important role in this paper.", "revisions": [ { "version": "v1", "updated": "2015-08-30T19:37:22.000Z" } ], "analyses": { "subjects": [ "11D61", "11R99", "11T99" ], "keywords": [ "positive characteristic", "monogenic orders", "finiteness results", "discriminant form equation", "delicate issues arise" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150807624B" } } }