In this paper we apply algebraic
-theory
techniques to construct a Fuglede–Kadison type determinant for a semifinite von
Neumann algebra equipped with a fixed trace. Our construction is based on the
approach to determinants for Banach algebras developed by Skandalis and de la Harpe.
This approach can be extended to the semifinite case since the first topological
-group
of the trace ideal in a semifinite von Neumann algebra is trivial. Along the way we
also improve the methods of Skandalis and de la Harpe by considering relative
-groups
with respect to an ideal instead of the usual absolute
-groups.
Our construction recovers the determinant homomorphism introduced by Brown,
but all the relevant algebraic properties are automatic due to the algebraic
-theory
framework.
Keywords
algebraic $K\mskip-2mu$-theory, semifinite von Neumann
algebras, determinants