{ "id": "2009.09297", "version": "v1", "published": "2020-09-19T20:54:29.000Z", "updated": "2020-09-19T20:54:29.000Z", "title": "Frattini-injectivity and Maximal pro-$p$ Galois groups", "authors": [ "Ilir Snopce", "Slobodan Tanushevski" ], "comment": "33 pages", "categories": [ "math.GR" ], "abstract": "We call a pro-$p$ group $G$ Frattini-injective if distinct finitely generated subgroups of $G$ have distinct Frattinis. This paper is an initial effort toward a systematic study of Frattini-injective pro-$p$ groups (and several other related concepts). Most notably, we classify the $p$-adic analytic and the solvable Frattini-injective pro-$p$ groups, and we describe the lattice of normal abelian subgroups of a Frattini-injective pro-$p$ group. We prove that every maximal pro-$p$ Galois group of a field that contains a primitive $p$th root of unity (and also contains $\\sqrt{-1}$ if $p=2$) is Frattini-injective. In addition, we show that many substantial results on maximal pro-$p$ Galois groups are in fact consequences of Frattini-injectivity. For instance, a $p$-adic analytic or solvable pro-$p$ group is Frattini-injective if and only if it can be realized as a maximal pro-$p$ Galois group of a field that contains a primitive $p$th root of unity (and also contains $\\sqrt{-1}$ if $p=2$); and every Frattini-injective pro-$p$ group contains a unique maximal abelian normal subgroup.", "revisions": [ { "version": "v1", "updated": "2020-09-19T20:54:29.000Z" } ], "analyses": { "subjects": [ "20E18", "12F10", "12G05", "22E20" ], "keywords": [ "galois group", "unique maximal abelian normal subgroup", "frattini-injective", "frattini-injectivity", "th root" ], "note": { "typesetting": "TeX", "pages": 33, "language": "en", "license": "arXiv", "status": "editable" } } }