Krasner Completions of Filtered Bands

Abstract

We introduce the Krasner completion of a band equipped with a decreasing filtration by subgroups of its unit group and give a criterion for reconstruction from its quotient bands. We recover the Krasner--Linzi inverse-limit theorem for valued fields. We also obtain a valuation ring analogue of the Krasner--Linzi theorem and compare Krasner completions of unit bands with adic completion.