Chia-Fu Yu

collaborators

3 papers

math.NT2026

Oort's conjecture on supersingular abelian varieties in odd characteristic

Valentijn Karemaker, Chia-Fu Yu

Oort's conjecture asserts that for any $g \geq 2$ and any prime $p$ , every geometric generic member in the supersingular locus $S_{g}$ has automorphism group ${\pm 1}$ .…

math.NT2024

Supersingular Ekedahl-Oort strata and Oort's conjecture

Valentijn Karemaker, Chia-Fu Yu

Let $A_{g}$ be the moduli space over $F_{p}$ of $g$ -dimensional principally polarised abelian varieties, where $p$ is a prime. We show that if $g$ is even…

math.NT2024

Uniqueness of indecomposable idempotents in algebras with involution

Valentijn Karemaker, Akio Tamagawa, Chia-Fu Yu

We prove uniqueness of a decomposition of $1$ into indecomposable Hermitian idempotents in an order of a finite-dimensional $Q$ -algebra with positive involution, by genera…