Workshop on birational geometry
March 11, 2022



Abstarcts



Konstantin Loginov (15.30-16.30)

K-stability of log Fano threefolds of Maeda type
Abstract. Log smooth log Fano threefolds with integral boundary were classified by H. Maeda in 1986. Unlike “classical”  Fano varieties, they are not bounded. Recently, K. Fujita introduced a class of log Fano varieites of Maeda type, which provides a natural playground for the study of K-stability of log Fano pairs (or, log K-stability). It turns out that, in the case of reducible boundary, in dimension 3 such pairs are K-unstable, with finitely many exceptions. We will discuss this result.

Ziquan Zhuang (17.00-18.00)

Boundedness of singularities and minimal log discrepancies of Kollár components 
Abstract. Several years ago, Chi Li introduced the local volume of a klt singularity in his work on K-stability. The local-global analogy between klt singularities and Fano varieties, together with recent study in K-stability lead to the conjecture that klt singularities whose local volumes are bounded away from zero are bounded up to special degeneration. In this talk, I will discuss some recent work on this conjecture through the minimal log discrepancies of Kollár components.

Yuchen Liu (18.30-19.30)

K-stability and moduli of quartic K3 surfaces
Abstract. We show that K-moduli spaces of (P^3, cS) where S is a quartic surface interpolates between the GIT moduli space and the Baily-Borel compactification as c varies in (0,1). We completely describe the wall crossings of these K-moduli spaces, hence verifying Laza-O’Grady’s prediction on the Hassett-Keel-Looijenga program for quartic K3 surfaces. We also obtain the K-moduli compactification of quartic double solids, and classify all Gorenstein canonical Fano degenerations of P^3. This is based on joint work with K. Ascher and K. DeVleming.