DMS Set Theoretic Topology Seminar

Speaker: Professor Vladimir Tkachuk  

Title: Every hereditarily Lindelof Sigma-space is cosmic

Abstract: We will start proving the nontrivial part of  Hodel’s famous  theorem  formulated in the title. The complete version of the theorem characterizes the cosmic spaces: it states that a space \( X\) is cosmic if and only if every subspace of \(X\) has the Lindelof Sigma-property.