{ "id": "1601.03622", "version": "v1", "published": "2016-01-14T15:26:36.000Z", "updated": "2016-01-14T15:26:36.000Z", "title": "Complete classification of 2-ramified power series", "authors": [ "Jonas Fransson" ], "categories": [ "math.NT" ], "abstract": "In this paper we study lower ramification numbers of power series tangent to the identity that are defined over fields of positive characteristics $p$. Let $g$ be such a series, then $g$ has a fixed point at the origin and the corresponding lower ramification numbers of $g$ are then, up to a constant, the degree of the first non-linear term of $p$-power iterates of $g$. The result is a complete classification of power series $g$ having ramification numbers of the form ${2(1+p+\\dots+p^n)}$. Furthermore, in proving said classification we explicitly compute the first significant terms of $g$ at its $p$th iterate.", "revisions": [ { "version": "v1", "updated": "2016-01-14T15:26:36.000Z" } ], "analyses": { "keywords": [ "complete classification", "study lower ramification numbers", "power series tangent", "first significant terms", "first non-linear term" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }