S spaces and L spaces, part 2

Seminar
Speaker
Roy Shalev (BIU)
Date
23/12/2020 - 16:00 - 14:00Add to Calendar 2020-12-23 14:00:00 2020-12-23 16:00:00 S spaces and L spaces, part 2 We introduce a new combinatorial principle which we call ♣_AD. This principle asserts the existence of a certain multi-ladder system with guessing and almost-disjointness features, and is shown to be sufficient for carrying out de Caux type constructions of topological spaces. Our main result states that strong instances of ♣_AD follow from the existence of a Souslin tree.  As an application, we obtain a simple, de Caux type proof of Rudin’s result that if there is a Souslin tree, then there is an S-space which is Dowker.   zoom אוניברסיטת בר-אילן - Department of Mathematics mathoffice@math.biu.ac.il Asia/Jerusalem public
Place
zoom
Abstract
We introduce a new combinatorial principle which we call ♣_AD. This principle asserts the existence of a certain multi-ladder system with guessing and almost-disjointness features, and is shown to be sufficient for carrying out de Caux type constructions of topological spaces.
Our main result states that strong instances of ♣_AD follow from the existence of a Souslin tree.  As an application, we obtain a simple, de Caux type proof of Rudin’s result that if there is a Souslin tree, then there is an S-space which is Dowker.

 

Last Updated Date : 21/12/2020