This paper will appear in the Proceedings of the 1994 Barcelona Conference on
Algebraic Topology. The inclusion of a ring of integers O into its number
field F induces a homomorphism f from the n-th homology group (with integral
coefficients) of the infinite special linear group over O to the n-th
homology group of the infinite special linear group over F. We prove the
following two theorems for any prime number p and any dimension n which is
small enough (depending on p): a) the homomorphism f is injective after
localization at p; b) all p-torsion divisible classes in the n-th homology
group of SL(F) belong to the image of f.
This paper has been published in "Algebraic Topoology: New Trends in
Localization and Periodicity", Proceedings of the 1994 Barcelona Conference
on Algebraic Topology, Progress in Mathematics 136 (1996) 23-31.