Ring stacks conjecturally related to the stacks $B{T}_n^{G,\mu }$

Abstract

Using the ring space of sheared Witt vectors, we define certain ring stacks. We suggest several models for the ring stacks. Motivation: there is a conjectural description of the stack of n-truncated Barsotti-Tate groups and its Shimurian analogs in terms of the new ring stacks.

Many minor corrections and edits