Inscription, twistors, and $p$-adic periods
Abstract
We introduce the theory of inscribed -sheaves, a differentiable extension of the theory of diamonds and -sheaves with internal tangent bundles that are often relative inscribed Banach-Colmez spaces, then apply this theory to the study of -adic periods. In particular, we construct natural inscribed versions of the Hodge and Hodge-Tate period maps and their lattice refinements for de Rham torsors, then compute the derivatives of these period maps in terms of classical structures in -adic Hodge theory. These torsors include infinite level global Shimura varieties and infinite level local Shimura varieties, and for these spaces we also give another moduli-theoretic construction of the inscribed structure; the construction in the local Shimura case applies more generally to the non-minuscule moduli of mixed characterisic local shtukas with one leg. The key new ingredients in our study of inscribed structures on -adic Lie group torsors over smooth rigid varieties over a -adic field are the Liu-Zhu period map, a refinement of the Hodge period map whose derivative is the geometric Sen morphism/canonical Higgs field, and a closely related exact tensor functor from -local systems to a category of twistor bundles on the relative thickened Fargues-Fontaine curve. These new structures are only visible after passing to the inscribed setting. We also discuss some possible implications of our computations in the vein of ``differential topology for diamonds."
Cite
@article{arxiv.2508.11589,
title = {Inscription, twistors, and $p$-adic periods},
author = {Sean Howe},
journal= {arXiv preprint arXiv:2508.11589},
year = {2026}
}
Comments
v2 - Section 10 updated to use Kim's results on Igusa stacks + other minor edits