collaborators

18 papers

math.AG2026

A cusp surface singularity is Frobenius liftable

Tatsuro Kawakami, Teppei Takamatsu

We show that a cusp surface singularity is Frobenius liftable. As a consequence, we determine all the Frobenius liftable surface singularities.

math.AG2026

An explicit formula for the Artin invariant of smooth K3 hypersurfaces

Teppei Takamatsu, Shou Yoshikawa

We characterize the Artin invariant of a smooth K3 hypersurface in terms of quasi--splitting. As an application, we obtain an explicit formula for this invariant.

math.AG2026

Finiteness of pointed families of symplectic varieties: a geometric Shafarevich conjecture

Lie Fu, Zhiyuan Li, Teppei Takamatsu +1

We investigate in this paper the so-called pointed Shafarevich problem for families of primitive symplectic varieties. More precisely, for any fixed pointed curve and any…

math.AG2026

Perfectoid pure thresholds of lifts of rational double points

Teppei Takamatsu, Shou Yoshikawa

We study the perfectoid pure threshold with respect to , an invariant of singularities in mixed characteristic arising from perfectoid purity. In this paper, we compute…

math.AG2026

Non-quasi--split canonical affine fourfolds exist in every characteristic

Teppei Takamatsu, Shou Yoshikawa

We construct canonical -factorial Gorenstein affine fourfolds in every positive characteristic that are not quasi--split.

math.AG2026

Quasi-F-splittings in birational geometry III

Tatsuro Kawakami, Teppei Takamatsu, Hiromu Tanaka +3

We prove that -Gorenstein quasi--regular singularities are klt. To this end, we shall introduce quasi-test ideals.