Existence of almost free abelian groups and reflection of stationary set

Saharon Shelah

Existence of almost free abelian groups and reflection of stationary set

Logic 2008-02-03 v1 Rings and Algebras

Authors: Saharon Shelah

Abstract

section 2: We answer a question of Mekler Eklof on the closure operations of the incompactness spectrum. We answer a question of Foreman and Magidor on reflection of stationary subsets of S_{< aleph_2}(lambda) = {a subseteq lambda : |a| < aleph_2}]. section 3 - NPT is not transitive. We prove NPT(lambda, mu) + NPT(mu, kappa) not => NPT(lambda, kappa)

Keywords

almost free abelian groups stationary reflection incompactness spectrum non-pcf transitive set theory

Cite

@article{arxiv.math/9606229,
  title  = {Existence of almost free abelian groups and reflection of stationary set},
  author = {Saharon Shelah},
  journal= {arXiv preprint arXiv:math/9606229},
  year   = {2008}
}