DMS Set Theoretic Topology Seminar

Speaker: Professor Vladimir Tkachuk

Title: Neither sigma-compactness nor Lindelof Sigma-property is discretely reflexive under CH

Abstract: We will construct, under the Continuum Hypothesis, an example of a space X in which the closure of every discrete set is countable (and hence sigma-compact) while X is not a Lindelof Sigma-space. Therefore, countability, sigma-compactness, and Lindelof Sigma-property all fail to be discretely reflexive under CH.