Gysin maps in oriented theories, by Alexander Nenashev
We prove that Gysin maps (transfer maps along closed embeddings of
smooth varieties) in an oriented cohomology theory are compatible with
compositions of closed embeddings. As opposed to the proof given by
Panin, we do not use characteristic classes of vector bundles. Our
proof is more straightforward. It is based on the properties of Thom
isomorphisms and the deformation to the normal cone isomorphisms.
Alexander Nenashev <nenashev@mathematik.uni-bielefeld.de>