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Cardinal Characteristics of Models of Set Theory

Logic 2018-11-14 v1

Abstract

We continue our investigation =of Shelah's interpretability orders κ\trianglelefteq^*_\kappa as well as the new orders κ×\trianglelefteq^\times_\kappa. In particular, we give streamlined proofs of the existence of minimal unstable, unsimple and nonlow theories in these orders, and we give a similar analysis of the hypergraph examples Tn,kT_{n, k} of Hrushovski. We also prove that if B\mathcal{B} is a complete Boolean algebra with the λ\lambda-c.c., then no nonprincipal ultrafilter on U\mathcal{U} λ+\lambda^+-saturates any unsimple theory.

Keywords

Cite

@article{arxiv.1811.05444,
  title  = {Cardinal Characteristics of Models of Set Theory},
  author = {Douglas Ulrich},
  journal= {arXiv preprint arXiv:1811.05444},
  year   = {2018}
}

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35 pages