Crystalline representations and -adic Hodge theory for non-commutative algebraic varieties
Keiho Matsumoto
Osaka University, Osaka-Fu, Japan

Abstract
In this paper, we study -adic Hodge theory for non-commutative algebraic varieties. Firstly, we propose a conjecture that for a complete discretely valued nonarchimedean extension of with perfect residue field and an -linear idempotent-complete, small smooth proper stable -category, there exists a -coefficient isomorphism preserving additional structures between the -local -theory on the generic fiber of and the topological periodic cyclic homology on the special fiber. This conjecture can be regarded as a non-commutative analog of the crystalline comparison theorem. We then proceed to prove the following results: the topological negative cyclic homology admits a Breuil–Kisin module structure, and the non-commutative analog of Bhatt–Morrow–Scholze’s comparison theorems holds. Additionally, we demonstrate that the -module obtained from the topological negative cyclic homology is a -lattice of a crystalline representation. Finally, we show that when the generic fiber of admits a geometric realization in the sense of Orlov, the non-commutative analog of the crystalline comparison theorem proposed by the author holds.
Cite this article
Keiho Matsumoto, Crystalline representations and -adic Hodge theory for non-commutative algebraic varieties. J. Noncommut. Geom. (2026), published online first
DOI 10.4171/JNCG/661