View source for Nottingham group

{{TEX|done}}{{MSC|20E18}}

The subgroup of automorphisms of the field of [[formal power series]] $\mathbf{F_p}[[t]]$ consisting of those automorphisms of the form $f(t) \mapsto f(g(t))$ where $g(t) \in t + O(t^2)$.  

It is a finitely generated, just infinite [[Pro-p group|pro-$p$ group]] of finite width. However, every separable pro-$p$ group can be embedded in it as a closed subgroup.

====References====
* Rachel D.  Camina, "Subgroups of the Nottingham group" ''J. Algebra'' '''196''' (1997) 101-113 {{ZBL|0883.20015}}