{ "id": "math/0602039", "version": "v5", "published": "2006-02-02T16:58:21.000Z", "updated": "2006-10-09T18:55:06.000Z", "title": "The Automorphism Group of a Finite p-Group is Almost Always a p-Group", "authors": [ "Geir T. Helleloid", "Ursula Martin" ], "comment": "38 pages, to appear in the Journal of Algebra; improved references, changes in terminology", "journal": "Journal of Algebra 312(2007) 294-329", "doi": "10.1016/j.jalgebra.2007.01.008", "categories": [ "math.GR", "math.CO" ], "abstract": "Many common finite p-groups admit automorphisms of order coprime to p, and when p is odd, it is reasonably difficult to find finite p-groups whose automorphism group is a p-group. Yet the goal of this paper is to prove that the automorphism group of a finite p-group is almost always a p-group. The asymptotics in our theorem involve fixing any two of the following parameters and letting the third go to infinity: the lower p-length, the number of generators, and p. The proof of this theorem depends on a variety of topics: counting subgroups of a p-group; analyzing the lower p-series of a free group via its connection with the free Lie algebra; counting submodules of a module via Hall polynomials; and using numerical estimates on Gaussian coefficients.", "revisions": [ { "version": "v5", "updated": "2006-10-09T18:55:06.000Z" } ], "analyses": { "subjects": [ "20E36", "05A16" ], "keywords": [ "automorphism group", "common finite p-groups admit automorphisms", "free lie algebra", "lower p-series", "lower p-length" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 38, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......2039H" } } }