# Topology Seminar

**
Wed., Mar. 10, 2021 1:00 p.m.
**

**
Location: Live Stream
**

**Speaker: **Don Stanley, University of Regina

**Title: **Commutative DG-algebras and rational homotopy theory

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

**Abstract: **Rational homotopy theory is modeled by the homotopy theory of (graded) commutative DG-algebras (CDGAs). We introduce the notion of rational equivalence of spaces, and then develop the theory of CDGAs. We start with some basic standard notation for CDGAs and then discuss equivalences and formality. We describe a number of examples of CDGAs and maps between them. Looking at the role of cofibrancy, we describe the difference between CDGAs and DGAs and finish with an example of a non-formal CDGA.