Omega-bounded ladder systems

Seminar
Speaker
Assaf Rinot
Date
04/01/2024 - 15:45 - 14:00Add to Calendar 2024-01-04 14:00:00 2024-01-04 15:45:00 Omega-bounded ladder systems Leiderman and Szeptycki proved that a single Cohen real introduces a ladder system L over w1 for which the corresponding space X_L is not a Delta-space. They asked whether there is a ZFC example of a ladder system L over some cardinal kappa for which X_L is not countably metacompact, in particular, not a Delta-space. In a paper from August, we gave an affirmative answer with kappa=cf(beth_{w+1}), but we got the feedback that the biggest interest is ladder systems consisting of ladders of order-type omega. In this talk, we'll prove that if aleph_w is a strong limit, then this extra requirement can be satisfied as well. This is joint work with Rodrigo Rey Carvalho and Tanmay Inamdar. Seminar room אוניברסיטת בר-אילן - Department of Mathematics mathoffice@math.biu.ac.il Asia/Jerusalem public
Place
Seminar room
Abstract

Leiderman and Szeptycki proved that a single Cohen real introduces a ladder system L over w1 for which the corresponding space X_L is not a Delta-space. They asked whether there is a ZFC example of a ladder system L over some cardinal kappa for which X_L is not countably metacompact, in particular, not a Delta-space. In a paper from August, we gave an affirmative answer with kappa=cf(beth_{w+1}), but we got the feedback that the biggest interest is ladder systems consisting of ladders of order-type omega. In this talk, we'll prove that if aleph_w is a strong limit, then this extra requirement can be satisfied as well.

This is joint work with Rodrigo Rey Carvalho and Tanmay Inamdar.

Last Updated Date : 01/01/2024