Lifting endomorphisms of formal A-modules over finite fields

摘要

Lubin conjectures that for an invertible series to commute with a noninvertible series with only simple roots of iterates, two such commuting power series must be endomorphisms of a single formal group. In this paper, we show that if the reduction of these two commuting power series are endomorphisms of a formal group, then themselves are endornorphisms of a formal group. (c) 2006 Elsevier Inc. All rights reserved.