activity
20242026
most citedPrismatic Kunz's theorem

1 citations · 1 across the 10 of their papers we have counts for

collaborators

10 papers

math.AG2026

Hodge--Tate splitting and Akizuki--Nakano vanishing in positive characteristic

Ryo Ishizuka, Shou Yoshikawa

We introduce the notion of Hodge--Tate splitting for schemes in positive characteristic. For a smooth variety over a perfect field of characteristic , we say that $X…

math.AC2026

Homological Detection by Perfectoid Algebras

Mohsen Asgharzadeh, Ryo Ishizuka

We first establish estimates for the projective and injective dimensions for quotients of perfectoid algebras by radical ideals. As applications, we obtain homological characteriza…

math.AC2026

On Perfectoidization of Finite Algebras over a Perfectoid Ring

Ryo Ishizuka, Léo Navarro Chafloque

We study general properties of the perfectoidization of finite algebras over a perfectoid ring, which helps to understand some precise and explicit descriptions. For example, we pr…

math.AC2026

Decomposition Theorem for Perfectoid Rings along General Ideals

Ryo Ishizuka, Léo Navarro Chafloque

Using André's lemma and the excision square for perfectoidization coming from -complete arc descent, we prove new structural results about perfectoid rings and perfectoidization…

math.AG2026

A local-global correspondence for perfectoid purity

Ryo Ishizuka, Shou Yoshikawa

We introduce (lim-)perfectoid splitting, which is a global variant of (lim-)perfectoid purity. Our main result establishes a correspondence between the lim-perfectoid splitting of…

math.AG2026

Algebraization of absolute perfectoidization via section rings

Ryo Ishizuka, Shou Yoshikawa

We construct and study a graded version of absolute perfectoidization for -graded adic rings. As a main geometric application, we show that the absolute perfectoidization of the…

math.AC2026

Derived graded modules

Ryo Ishizuka, Shou Yoshikawa

We introduce the notion of the -category of (complete) derived -graded modules over a -graded ring for a torsion-free abelian group , and we study its foundati…

math.AC2025

Graded perfectoid rings

Ryo Ishizuka, Shou Yoshikawa

We introduce and study graded perfectoid rings as graded analogues of Scholze's (integral) perfectoid rings. We establish a categorical equivalence between graded perfectoid rings…

math.AC2024

Perfectoid towers generated from prisms

Ryo Ishizuka

We present a unified construction of perfectoid towers from specific prisms which covers all the previous constructions of (p-torsion-free) perfectoid towers. By virtue of the cons…

math.AC2024★ 1 cited

Prismatic Kunz's theorem

Ryo Ishizuka, Kei Nakazato

In this paper, we prove "prismatic Kunz's theorem" which states that a complete Noetherian local ring of residue characteristic is a regular local ring if and only if the F…