报告题目：Analytic automorphisms, composition operators and the representation of analytic functions

　　报告人：侯秉喆教授

　　报告时间：2023.12.7 16：30-17：30

　　报告地点：数学与统计学院 104报告厅

　　报告人简介：侯秉喆，于2008年获得吉林大学理学博士学位，现为吉林大学数学学院教授，主要从事基础数学的教学与研究，主要研究方向为算子理论与算子代数，拓扑与拓扑动力系统等，在Sci China Math., Journal of Operator Theory, Proc. Amer. Math. Soc., Topol. App. 等学术期刊发表论文三十余篇。

　　报告内容简介：In this talk, we focus on the weighted Hardy spaces of polynomial growth, which cover the classical Hardy space, weighted Bergman spaces, weighted Dirichlet spaces and much broader. We discuss the boundedness of the composition operators with symbols of analytic automorphisms of unit open disk (finite Blaschke product and analytic functions on the unit closed disk) acting on weighted Hardy spaces of polynomial growth. Furthermore, we could compute the K_0-groups of the commutant algebras of those multiplication operators. Then, the Jordan decomposition theorem and similar classification for the representation of analytic functions on the unit closed disk as multiplication operators are obtained. Moreover, we also study the norms, spectra and (semi-)Fredholmness of composition operators induced by disc automorphisms. This is a joint work with Prof. Chunlan Jiang.