TOPOLOGY SEMINAR

**"Homotopy Classification
of PD_4-Complexes"**

By

**Abstract: ****In this talk we define an order relation among oriented
PD_4-complexes.We show that with respect to this relation, two PD_4-complexes
over the same complex are homotopy equivalent if and only if there is an
isometry between the second homology groups. We also consider minimal objects
of this relation. This is a joint work with Friedrich Hegenbarth and Dusan
Repovs.**

**Date: ****Monday, November 2, 2015**

**Time: ****13.40 – 14:30**

**Place: ****Mathematics Seminar Room,
SA-141**

**All are most cordially invited.
Tea and cookies will be served after the talk.**