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The Category Dichotomy for Ideals

2025/03/04 by Dow, Alan, Figueroa-Sierra, Raul, Guzmán, Osvaldo +1
#03E05 #03E17 #03E75 #F.4.1 #FOS: Mathematics #Logic (math.LO)

paper · doi:10.48550/arxiv.2503.02290

Abstract

We provide a counterexample to the Category Dichotomy in the framework of \textsfZFC. That is, we prove the existence of an ideal on ω that is not Katětov below nwd and does not have restrictions above ED. We also prove that in the Laver model every tall P-ideal is Katětov-Blass above EDfin and that it is consistent that every Q+ ideal is meager.

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