A friendly iteration forcing that the four cardinal characteristics of $\mathcal E$ can be pairwise different

Autorzy

Dane publikacji

  • DOI: 10.4064/cm8917-2-2023

  • Tom 173

  • Zeszyt 1

  • Czasopismo: Colloquium Mathematicum

  • Strony: 123-157

  • Data publikacji online: 10.04.2023

Liczba wyświetleń: 0

Liczba pobrań: 0

Abstrakt

Let $\mathcal E$ be the $\sigma $-ideal generated by the closed measure zero sets of reals. We use an ultrafilter-extendable matrix iteration of ccc posets to force that, for $\mathcal E$, their associated cardinal characteristics (i.e. additivity, covering, uniformity, and cofinality) are pairwise different.