A conductor formula for completed group algebras

Abstract

Let o be the ring of integers in a �nite extension of Qp. If G is a �nite group and Γ is a maximal order containing the group ring oG, Jacobinski's conductor formula gives a complete description of the central conductor of Γ into oG in terms of characters of G. We prove a similar result for completed group algebras o[[G]], where G is a p-adic Lie group of dimension 1. We will also discuss several consequences of this result.