Bivariant intersection theory

We will see how to generalise the notion of Gysin homomorphisms, which will define bivariant class groups. These will give us access to a unified framework to discuss both cohomology and homology. We will see that they come wiht many natural operations. We will also see natural spaces that Chern classes live in and discuss Poincaré duality as well as discussing how some of the theorems we previously proved generalise to bivariant class groups.