Jungkai
Chen (National Taiwan University & NCTS)
Title.
Toward classification of threefold
divisorial contractions to curves
Abstract.
Mimimal model program is a fundamental
tool of birational geometry. In dimension three and
characteristic zero, singularties are better understood
and hence many geometric properties can be described
explicitly. For example, threefolds divisorial
contractions to points are classified thanks to the work
of Kawamata, Hayakawa, Kawakita and others.
In this talk, we will present the recent
progress toward the classification of threefold
divisorial contractions to curves. Most of the materials
are joint work in progress with Jheng-Jie Chen and
Hsin-Ku Chen.
Title.
Roger Apéry and the threefold that Fano
missed.
Konstantin Loginov (Steklov Institute &
Laboratory of Algebraic Geometry, HSE)
Title. Coregularity of smooth Fano
threefolds.
Abstract. A natural
way to study Fano varieties is by looking at its
(pluri-)anti-canonical divisors. Coregularity measures
how singular such divisors could be. We explain how to
compute the coregularity of smooth Fano varieties of
dimension 3.
Keiji
Oguiso (The University of Tokyo)
Title. An abelian fibered
Calabi-Yau threefold with a relative automorphism of
positive entropy.
Abstract. Positivity of entropy of an automorphism
plays a substantial role in both algebraic dynamics and
algebro-geometric study of automorphisms of projective
varieties, as a measure of complexities of
automorphisms. For surfaces including abelian surfaces
and K3 surfaces, there are many concrete examples of
automorphisms of positive entropy. In this talk, I would
like to point out one sharp contrast between abelian
fibered Calabi-Yau threefolds and K3 fibered Calabi-Yau
threefolds in the view of entropy of relative
automorphisms. More precisely, among other relevant
results, I would like to show that there is exactly one
abelian fibered Calabi-Yau threefold with relative
automorphism of positive entropy up to isomorphisms as
fibered varieties (explicit), whereas there are many
examples of K3 fibered Calabi-Yau threefolds.with
relative automorphisms of positive entropy.