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

Abstract

Let $X=\mathrm{Spf}({\mathcal{O}}_K)$. We classify perfect complexes of $n$-truncated prismatic crystals on the prismatic site of $X$ when $n\le 1+\frac{p-1}{e}$ 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.