Abstract.It is proved that a connected complete separable ANR Z that satisfies the discrete n-cells property admits dense embeddings of every «-dimensional o-compact, nowhere locally compact metric space X(n e N U {0, oo}). More generally, the collection of dense embeddings forms a dense Gs-subset of the collection of dense maps of X into Z. In particular, the collection of dense embeddings of an arbitrary o-compact, nowhere locally compact metric space into Hubert space forms such a dense Cs-subset. This generalizes and extends a result of Curtis [Cu,]. 0. Introduction. In [Cu,], D. W. Curtis constructs dense embeddings of a-compact, nowhere locally compact metric spaces into the separable Hilbert space l2. In this paper, we extend and generalize this result in two distinct ways: first, we show that any dense map of a a-compact, nowhere locally compact space into Hilbert space is strongly approximable by dense embeddings, and second, we extend this result to finite-dimensional analogs of Hilbert space. Specifically, we prove Theorem. Let Z be a complete separable ANR that satisfies the discrete n-cells property for some w e ÍV U {0, oo} and let X be a o-compact, nowhere locally compact metric space of dimension at most n. Then for every map f: X -» Z such that f(X) is dense in Z and for every open cover <% of Z, there exists an embedding g: X -> Z such that g(X) is dense in Z and g is °U-close to f.We actually prove a slightly stronger version of the Theorem. We prove that the collection of dense embeddings of X into Z forms a dense C7s-subset of the collection of dense maps of X into Z topologized by the limitation topology.
Corollary.Let n and Z be as in the Theorem with the added assumption that Z is connected. Then Z admits a dense embedding of every a-compact, nowhere locally compact metric space X of dimension at most n.Proof. It suffices to show that there is at least one map X -> Z whose image is dense in Z. Let R denote the following subset of the plane:R is a separable AR and since X is noncompact, there is a map of X onto a dense subset of R. (Let {x,} be a countable closed discrete subset of X and {/-,.} a