The Urysohn universal space is a certain metric space that contains all separable metric spaces in a particularly nice manner. This mathematics concept is due to Pavel Urysohn, who presented an explicit construction. Another construction has been subsequently developed by Felix Hausdorff and a more general notion was discussed by Miroslav Katětov.[1]
- ^ Miroslav Hušek, Urysohn universal space, its development and Hausdorff's approach, Topology and its Applications, Volume 155, Issue 14, 2008, Pages 1493-1501 doi:10.1016/j.topol.2008.03.020