activity
20242026
collaborators

8 papers

math.AG2026

Sixteen generators of the automorphism group of the Fermat quartic surface

JongHae Keum, Keiji Oguiso, Xun Yu

It has been a long standing open problem to find generators of the automorphism group of the complex Fermat quartic K3 surface; in fact, even an explicit number of generators has n…

math.AG2026

Obstructions for codimension one multiple fibers of Lagrangian and Calabi--Yau fibrations

Yoon-Joo Kim, Keiji Oguiso, Evgeny Shinder

We prove that compact hyper-Kähler manifolds with a Lagrangian fibration over a projective space have no multiple fibers in codimension one. This has several consequences for the s…

math.AG2026

On K3 surfaces with hyperbolic automorphism groups

Koji Fujiwara, Keiji Oguiso, Xun Yu

We show the finiteness of the Néron-Severi lattices of complex projective K3 surfaces whose automorphism groups are non-elementary hyperbolic with explicit descriptions, under the…

math.AG2025

Essential dimensions of polarized endomorphisms of abelian varieties

Yujie Luo, Keiji Oguiso, De-Qi Zhang

Let be a polarized endomorphism of an abelian variety . Kollár and Zhuang asked whether the essential dimension equals . We provide counte…

math.AG2025

Polynomial log-volume growth in slow dynamics and the GK-dimensions of twisted homogeneous coordinate rings

Hsueh-Yung Lin, Keiji Oguiso, De-Qi Zhang

Let f be a zero entropy automorphism of a compact Kähler manifold X. We study the polynomial log-volume growth Plov(f) of f in light of the dynamical filtrations introduced in our…

math.AG2025

On the virtual invariants of zero entropy groups of compact Kähler manifolds

Tien-Cuong Dinh, Hsueh-Yung Lin, Keiji Oguiso +1

Let be a compact Kähler manifold. We study subgroups of biholomorphic automorphisms of zero entropy when is compact (e.g. when $\ma…