Modeling Group Actions on Stacks (Especially the Lubin-Tate Action)

Abstract

Suppose we are given a profinite group $G$ acting on a formal moduli stack $\mathcal{M}$, and we want to understand the group action, and compute cohomology related to this group action. How can we do it? This prolegomenon surveys two methods of pinning down such an action: geometric modeling and the two tower method. We highlight their use on a specific action - the automorphisms of a formal group acting on its deformation space, called the Lubin-Tate action.