Boise Set Theory Seminar
Thursday, February 28 from 1:30 to 2:30pm
Speaker: Samuel Coskey
Title: Urysohn spaces
Is there a single separable metric space which contains all the others? This question was answered in the 1920’s by Banach and Mazur, who showed that $C[0,1]$ is such a space. But around the same time Urysohn gave another example (now called Urysohn space $U$) which additionally exhibits strong symmetry properties. Recently Urysohn’s construction has found numerous generalizations and applications. I’ll give a (modern) presentation of the construction, and briefly mention a couple of these recent results.