报告人：何伟鲲
报告时间：11月25日下午2点
报告地点：立德楼511
腾讯会议：714-952-659
题目：Spectral gap in subgroups of SL_d(Z/nZ)
摘要：Uniform spectral gap (of the discrete Laplace operators) of a family of finite groups is also known as expansion in groups or property (tau). In the case of SL_2(Z/nZ), a uniform spectral gap is present as a consequence of Selberg's 3/16 theorem and the Burger-Brooks correspondence. In this talk, I will explain how to show uniform spectral gap in broader classes of groups, using combinatorics and dynamics. This talk is based on a joint work with Nicolas de Saxcé, which is built on works of Bourgain-Gamburd and Bourgain-Varju among others.
报告人简介：何伟鲲，2017年博士毕业于巴黎第十一大学。随后分别在耶路撒冷希伯来大学与韩国高等研究院任博士后。2022年初入职中国科学院数学与系统科学研究院，任副研究员。研究兴趣包含齐次动力系统、分形几何、几何群论以及加性组合。主要研究成果发表在Duke Math. J., JEMS等期刊上。