# Topology Seminar

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Wed., Nov. 4, 2020 4:30 p.m.
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Location: Live Stream
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**Speaker: **Yu Zhang, Nankai University

**Title: **Koszul duality and TQ-homological Whitehead theorem of structured ring spectra

**Zoom:** https://uregina-ca.zoom.us/j/99127226830?pwd=bnFQR1R3UUdyWUxqSS9JMExMRlZwZz09

**Abstract: ** Quillen's work on rational homotopy theory illustrates the duality between differential graded Lie algebras and differential graded cocommutative coalgebras. In homotopy theory, there is an analogous duality phenomenon, called Koszul duality, where the role of differential graded algebras is played by structured ring spectra. In this talk, I will talk about Koszul duality as well as some of my related recent work on Topological Quillen (TQ) localization and the homological Whitehead theorem of structured ring spectra. This is joint with John E. Harper.