报告题目：Quasi-local algebras and asymptotic expanders

报 告 人：章嘉雯 青年副研究员 复旦大学

报告时间：2021年6月17日  13:30-14:30

报告地点：腾讯会议 ID：826 579 543密码：0617

校内联系人：张远航 zhangyuanhang@jlu.edu.cn

报告摘要：Roe algebras are C*-algebras associated to metric spaces, which encode their large scale structures. These algebras play a key role in higher index theory, providing a bridge between geometry, topology and analysis. We study a quasi-local perspective on Roe algebras, which leads to a larger index algebra called the quasi-local algebra.

Based on the idea of quasi-locality, we introduce a graphic notion called asymptotic expanders which generalise the classic one of expanders. Using a structure theorem, we show that asymptotic expanders cannot be coarsely embedded into any Hilbert space and hence construct new counterexamples to the coarse Baum-Connes conjecture.

This is a joint project with Ana Khukhro, Kang Li, Piotr Nowak, Jan Spakula and Federico Vigolo.

报告人简介：章嘉雯，复旦大学数学科学学院青年副研究员，主要从事非交换几何领域的研究。近些年围绕Roe代数的刚性、几何群论的一些核心问题上取得一系列研究成果。在TAMS、JFA、Selecta Math.等重要期刊已发表多篇科研论文。