# Marion Scheepers: Countable tightness

February 22, 2012

Speaker: Marion Scheepers

Title: Countable tightness
Abstract: Countable tightness is for general topological spaces a weakening of the property of having a countable neighborhood base. It also is a property that is fragile under generic extensions of the set theoretic universe. In this talk we give a brief survey of some important open problems about countable tightness, and some recent findings about the fragility of countable tightness
under generic extensions.