### Gysin maps in Balmer-Witt theory, by Alexander Nenashev

We introduce twisted Thom operators and the deformation to the normal cone
isomorphisms in the derived Witt theory. Using these ingredients, we define
push-forward maps of Witt groups along closed embeddings of smooth varieties
and prove their standard properties, a most delicate of which turns out to be
the functoriality of such maps.

Alexander Nenashev <nenashev@gl.yorku.ca>