講演情報

2024年 前期

日程：2024年 7月12日（金）16:30 - 18:00
教室：早稲田大学 西早稲田キャンパス 51号館 18-12
講演者：吉野 太郎 氏 (東京大学) 
タイトル：Introduction to mock toric varieties
アブストラクト：
In this talk, I introduce new toroidal varieties - mock toric varieties.
For example, toric varieties are mock toric varieties, and a surface given by blowing up the projective plane in finite k-rational points is a mock toric variety.
Mock toric varieties have similar properties to toric varieties, and we can generalize Khovanskii's results about the resolution of Newton non-degenerate hypersurfaces in toric varieties for ones in mock toric varieties.
In application, I mention the irrationality of a very general hypersurface in the complex Grassmannian variety Gr(2, n). 

2024年度 前期

日程：2024年 7月2日（火）17:00 - 18:30 （いつもと日程が異なります，ご注意ください）
教室：早稲田大学 西早稲田キャンパス 51号館 18-08
講演者：鈴木 拓 氏 (宇都宮大学) 
タイトル：Higher order minimal families of rational curves and Fano manifolds with positive Chern characters
アブストラクト：
The purpose of my talk is to discuss higher order minimal families of rational curves on Fano manifolds.
First we review previous study of Fano manifolds whose Chern characters satisfy some positivity condition, and then we mention recent progress.
We also show that such manifolds are covered by high dimensional rational manifolds.

日程：2024年 6月14日（金）16:30 - 18:00
教室：早稲田大学 西早稲田キャンパス 51号館 18-12
講演者：榎園 誠 氏 (立教大学) 
タイトル：Semistable reduction for complex analytic spaces
アブストラクト：
Semistable reduction theorem asserts the existence of a relative analogue of resolutions of singularities for any given morphism between geometric objects.
This theorem for algebraic varieties in characteristic 0 has been extensively studied by many researchers.
In this talk, we will discuss the semistable reduction problem in the complex analytic category and explain that the semistable reduction theorem holds for projective morphisms over Stein spaces.
We will also explain the idea of the proof and an application to the minimal model program for complex analytic varieties.
This talk is based on the joint work with K. Hashizume.

日程：2024年 5月24日（金）16:30 - 18:00
教室：早稲田大学 西早稲田キャンパス 51号館 18-12
講演者：原 和平 氏 (東京大学 Kavli IPMU)
タイトル：Rank two weak Fano bundles over the del Pezzo threefold of degree five
アブストラクト：
This talk discusses the classification problem of rank two weak Fano bundles over Fano threefolds of Picard rank one, especially the del Pezzo threefold of degree five.
The classification itself will not be quite explained, but instead of that, some key theorems that are used in the classification will be provided with sketch of proofs.
Namely, we discuss the global generation of bundles, and resolutions of bundles in terms of natural vector bundles.
All the contents of this talk depends on the joint work with T.Fukuoka and D.Ishikawa.