# Marcin Michalski: Universal sets for bases of $\sigma$-ideals

Tuesday, November 8, 2016, 17:15
Wrocław University of Technology, 215 D-1

Speaker: Marcin Michalski (Wrocław University of Science and Technology)

Title: Universal sets for bases of $\sigma$-ideals

Abstract:

We shall construct universal sets of possibly low Borel rank for classic $\sigma$-ideals of sets: $\mathcal{N}$-family of measure zero sets, $\mathcal{M}$-family of meager sets, $\mathcal{M}\cap\mathcal{N}$ and $\mathcal{E}$. We will also discuss briefly cases of other ideals.