### Products and Duality in Categories with Cofibration and Weak Equivalences, by M. S. Weiss and Bruce Williams

The natural transformation from Wall's L-theory to the Tate
cohomology of Z/2 acting on K-theory (which we
constructed in earlier papers) commutes with external products.
Corollary: the Tate cohomology of Z/2 acting on the K-theory
of any ring with involution is a generalized Eilenberg-MacLane
spectrum, and it is 4-periodic.

M. S. Weiss <msweiss@math.lsa.umich.edu>

Bruce Williams <bruce@bruce.math.nd.edu>