### Transfer Functors on k-Algebras, by Charles A. Weibel

We introduce and study the notion of a *transfer functor* for
normal algebras over a field, i.e., a functor equipped with transfer
maps for finite integral extensions. The prototypical transfer
functors are: the forgetful functor F(A)=A, equipped with trace maps,
and the units functor U(A)=A^{*}, equipped with norm maps.
Any Hecke functor for the absolute Galois group (such as a Galois
module) induces a transfer functor, and conversely.

Our notion is a modification of Voevodsky's notion of *presheaf with
transfers,* taking advantage of the fact that every correspondence
may be normalized, and is inspired by the work of Suslin and Voevodsky.

This paper appeared in *J. Pure Applied Algebra* 201 (2005), 340-366.

Charles A. Weibel <weibel@math.rutgers.edu>