Optimal Bounds for Algebraic Invariants of Surfaces

2023-04-04 08:59:02

时间:2023年4月10日(星期一)10:00-11:00

地点:西湖大学云谷校区E4-201


主讲人:Jihao Liu, Northwestern University

报告题目:Optimal Bounds for Algebraic Invariants of Surfaces

报告摘要:In this talk, I will present several results on the optimal bounds for algebraic invariants of surfaces. Specifically, I will discuss our findings of the 1-gap of R-complementary thresholds, the smallest volume of ample log surfaces with reduced boundary, and the smallest minimal log discrepancy of klt Calabi-Yau surfaces. These results answer questions posed by V. Alexeev and W. Liu, and J. Kollár, and also reprove a recent result by L. Esser, B. Totaro, and C. Wang. As an application, I will also discuss our work on finding and classifying all exceptional Fano surfaces (Fano surfaces with Tian's alpha invariant strictly greater than 1) that are not 1/11-klt. We have identified 25 such surfaces up to isomorphism, none of which have been previously documented in the literature. If time allows, I will also touch upon a question we have developed regarding the 1-gap of R-complementary thresholds and the 1-gap of minimal log discrepancies in high dimensions. This is an ongoing joint work with V. V. Shokurov.