DMS Colloquium: Ziqin Feng

Speaker: Ziqin Feng

Title: Tukey Order, Metrizability, and Others

Abstract: A directed set is a partially ordered set such that any finite elements have an upper bound. The cofinal complexity of partially ordered sets is normally compared by an ordering called Tukey ordering. Tukey order has been intensely studied in different topics in topology and analysis. It has been successfully used in tackling problems in these topics. In this talk, I will present the application of Tukey order in the metrizability problems arising in functional analysis, and some other results in projects which are related to directed sets. My recent work on free topological groups will also be presented.