时间：2021年9月22日（周三）上午9:30-12:00

Time：9:30-12:00 AM, September 22, 2021

地点：西湖大学云栖校区4号楼409-411教室

Venue: Room 409-411, Building 4, Yunqi Campus, Westlake University

主持人：西湖大学理学院 赵永强/赵以庚 博士

Host: Dr. Yongqiang Zhao and Dr. Yigeng Zhao, School of Science, Westlake University

主讲嘉宾/Speaker：Prof. Lei Song, Sun Yat-sen University

题目/Title：Inner Projection and Castelnuovo-Mumford Regularity of Structure Sheaves

摘要/Abstract:

    Castelnuovo-Mumford regularity in a sense measures the complexity of coherent sheaves on a projective space. A. Noma established a sharp bound for the C-M regularity of structure sheaves of smooth subvarieties. A key tool is his classification of projective subvarieties via generic inner projection. I will explain Noma's classification, and show how blending it with the positivity of double-point divisors and the theory of multiplier ideals leads to the same bound for normal projective varieties with at worst isolated, Q-Gorenstein singularities. By contrast, such a bound fails for varieties in general. This is based on a joint work with J. Moraga and J. Park.

讲座联系人/Contact:

理学院 王老师  wangqiuhui@westlake.edu.cn