Hong Kong Geometry Colloquium

November 25, 2006 (Saturday)

Room 517, Meng Wah Complex, HKU

 


 

Professor Jungkai Chen

National Taiwan University, Taipei

On varieties with k = 0

 

Abstract

In algebraic geometry, the varieties of Kodaira dimension k = 0 play an important role in many aspects. For example, elliptic curves, abelian varieties, K3 surfaces, and Calabi-Yau varieties are varieties with k = 0. Moreover, in classification theory, the natural Iitaka fibration constructed via pluricanonical maps produces an algebraic fiber space with general fiber having k = 0.

Turning to the structure of varieties X with k(X) = 0, it's conjectured by Ueno that:

1. The Albenese map alb: X ® Alb(X) is surjective to the abelian variety Alb(X) with connected fibers,

2. The general fiber F of alb has k(F) = 0, and

3. After base change by a finite etale morphism A' ® Alb(X), X'= X ´A' Alb(X) is birational to A' ´ F.

Kawamata has proved that (1) is always true and the whole conjecture holds when a good minimal model exists. The purpose of this talk is to present our recent progress toward this conjecture. This is a joint work with Hacon.