Non-reflection of the bad set for check I_theta[lambda] and pcf

2012/06/10 by Saharon Shelah, Shelah, Saharon · 1 citation
Mathematics · #Rings, Modules, and Algebras #Commutative Algebra and Its Applications #Advanced Topology and Set Theory

paper · pdf · doi:10.48550/arxiv.1206.2048

Abstract

We reconsider here the following related pcf questions and make some advances: (Q1) concerning the ideal check I_kappa [lambda] how much reflection do we have for the bad set S^bd_{lambda, kappa} subseteq delta < lambda : cf(delta)= kappa assuming it is well defined? (Q2) for an ideal J on kappa how large are S^bd_J[f],S^ch_J[f] for f=< f_alpha : alpha which is

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• Quite free complicated abelian group, PCF and Black Boxes

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