R. Geoghegan and A. Nicas 
Fixed point theory and the K-theoretic trace 
Proceedings of Conference (1996) on Dynamical Zeta Functions, 
Nielsen Theory and Reidemeister Torsion, Banach Center, Warsaw

Abstract. The relationship between fixed point theory and $K$-theory is
explained, both classical Nielsen theory (versus $K_0$) and $1$-parameter
fixed point theory (versus $K_1$). In particular, various zeta functions
associated with suspension flows are shown to come in a natural way as
"traces" of "torsions" of Whitehead and Reidemeister type.