On the prismatization of $O_K$ beyond the Hodge-Tate locus

TL;DR

This paper classifies perfect complexes of prismatic crystals on a formal scheme over a p-adic ring beyond the Hodge-Tate locus, linking prismatic theory with Galois representations and de Rham crystals.

Contribution

It extends the classification of prismatic crystals to the case beyond the Hodge-Tate locus and describes associated Galois representations and their cohomology.

Findings

Classified perfect complexes of prismatic crystals for n ≤ 1+(p-1)/e.

Described the category of Galois representations via rationalized vector bundles.

Classified integral models for de Rham prismatic crystals.

Abstract

Let $X=\mathrm{Spf}(\mathcal{O}_K)$. We classify perfect complexes of $n$-truncated prismatic crystals on the prismatic site of $X$ when $n\leq 1+\frac{p-1}{e}$ by studying perfect complexes on the $n$-truncated prismatization of $X$, which are certain nilpotent thickenings of the Hodge-Tate stack of $X$ inside the prismatization of $X$. We describe the category of continuous semilinear representations and their cohomology for $G_K$ with coefficients in $B_{\mathrm{dR},n}^+$ via rationalization of vector bundles on the slight shrinking of the $n$-truncated prismatization of $X$. Along the way, we classify certain integral models for de Rham prismatic crystals studied in arXiv:2205.14914.