Shou Yoshikawa

collaborators

3 papers

math.AG2026

A Criterion for Perfectoid Purity and the Rationality of Thresholds

Shou Yoshikawa

We introduce a new criterion providing a sufficient condition for a hypersurface in an unramified regular local ring to be perfectoid pure. The criterion is formulated in terms of…

math.AC2026

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.NT2026

Classifications of Hecke Fields and Galois Images of Weight One Exotic Newforms

Ryotaro Sakamoto, Sho Yoshikawa

We determine the Hecke fields associated with weight one newforms of $A_{4}$ -, $S_{4}$ -, and $A_{5}$ -type, expressed in terms of the order of its nebentypus. Furthermore, for each type,…