COSAM » Events » 2019 » March » DMS Set Theoretic Topology Seminar

 DMS Set Theoretic Topology Seminar Time: Mar 27, 2019 (02:00 PM) Location: Parker Hall 246 Details: Speaker: Ziqin Feng will continue Abstract: Let $$X$$ and $$Y$$ be spaces.   $$X$$ is said to be $$Y$$-selective if every lower semicontinuous mapping from $$Y$$ to the nonempty closed subsets of $$X$$ has a continuous selection.  Let $$L$$ be a convergent sequence with limit point; e.g., $$L={1/n: n=1,2,…} \cup {0}$$.  Assuming Martin’s Axiom, we construct a space $$X$$ which is $$L$$-selective but not $$Q$$-selective, where $$Q$$ is the space of rational numbers.  It is not known if there is such an example in ZFC.

Last updated: 03/26/2019