Orateur
Description
The syntomification of the integers (Z_p^syn) acts as a parameter space for p-adic cohomology theories. By the work of Drinfeld and others, it is known to carry a canonical formal group, and hence a map to the moduli stack of formal groups. Pulling back along this map gives rise to a certain line bundle equipped with a distinguished section "v_1". On the p-completed moduli stack of formal groups, the nonvanishing of v_1 defines the substack parametrizing "height-1" formal groups. Yet the preimage of this locus on Z_p^syn, when computed in p-adic formal stacks is empty. There is a mismatch here because inverting v_1 on syntomic cohomology gives p-adic étale cohomology, but inverting it on the stack itself before passing to global sections gives nothing.
I will explain how passing to analytic stacks brings this missing locus into view. By realizing the p-completed moduli stack of formal groups as an analytic stack, we construct an algebro-geometric shadow of K(1)-localization. Applied to syntomification, this produces an analytic stack whose dualizable quasi-coherent sheaves recover p-adic Galois representations, and more generally lisse étale sheaves on the generic fiber of a p-adic formal scheme. Time permitting, I will explain how a perfected version of this construction depends only on the generic fiber, providing a geometric counterpart to purity results for K(1)-localized K-theory. This is joint work in progress with Greg Andreychev.