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arXiv:1208.5424math.LO

Cofinality spectrum theorems in model theory, set theory and general topology

M. Malliaris, S. Shelah

Abstract

We connect and solve two longstanding open problems in quite different areas: the model-theoretic question of whether $SOP_2$ is maximal in Keisler's order, and the question from set theory/general topology of whether $\mathfrak{p} = \mathfrak{t}$, the oldest problem on cardinal invariants of the continuum. We do so by showing these problems can be translated into instances of a more fundamental problem which we state and solve completely, using model-theoretic methods.

arXiv comments
60 pages. Editorial and expository changes from previous version. Accepted, Journal of the AMS
Journal reference
DOI
Subjects
math.LOLogic math.GNGeneral Topology

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    • Actual article: https://arxiv.org/pdf/1208.5424.pdf Great results within a very narrow field, which quantamagazine leverages into a clickbaity title.

      xamuelView on HNParent context

    • Disclaimer: I have a math background, but this isn't my field. The continuum hypothesis was proved to be independent of ZFC. From glancing at the first few paragraphs of the actual paper [2], it's been established for decades that the following inequality holds: aleph_1 <= p <=…

      v64View on HNParent context

    • p and t are implicitly defined cardinalities (i.e., the smallest cardinalities with given properties). See Definition 1.1 of the source article (https://arxiv.org/pdf/1208.5424.pdf)

      clintoncView on HNParent context

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