Boletim da Sociedade Paranaense de Matemática (Nov 2002)
Hausdorff Nonstandard Extensions
Abstract
We introduce the notion of Hausdorff extension of an arbitrary set Xand we study the connections with the Stone-Cech compactification beta X of the discrete space X. We characterize those Hausdorff extensions that satisfy the “transfer principle” of nonstandard analysis, and we investigate the consistency strength of their existence.