Inner models with large cardinal features usually obtained by forcing

  • A. Apter, V. Gitman, and J. D. Hamkins, “Inner models with large cardinal features usually obtained by forcing,” Archive for Mathematical Logic, vol. 51, pp. 257-283, 2012. (10.1007/s00153-011-0264-5)  
    @article {ApterGitmanHamkins2012:InnerModelsWithLargeCardinals,
    author = {Apter, Arthur and Gitman, Victoria and Hamkins, Joel David},
    affiliation = {Mathematics, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA},
    title = {Inner models with large cardinal features usually obtained by forcing},
    journal = {Archive for Mathematical Logic},
    publisher = {Springer Berlin / Heidelberg},
    issn = {0933-5846},
    keyword = {Mathematics and Statistics},
    pages = {257--283},
    volume = {51},
    issue = {3},
    url = {http://jdh.hamkins.org/innermodelswithlargecardinals/},
    eprint = {1111.0856},
    archivePrefix = {arXiv},
    primaryClass = {math.LO},
    doi = {10.1007/s00153-011-0264-5},
    note = {10.1007/s00153-011-0264-5},
    year = {2012}
    }

We construct a variety of inner models exhibiting features usually obtained by forcing over universes with large cardinals. For example, if there is a supercompact cardinal, then there is an inner model with a Laver indestructible supercompact cardinal. If there is a supercompact cardinal, then there is an inner model with a supercompact cardinal $\kappa$ for which $2^\kappa=\kappa^+$, another for which $2^\kappa=\kappa^{++}$ and another in which the least strongly compact cardinal is supercompact. If there is a strongly compact cardinal, then there is an inner model with a strongly compact cardinal, for which the measurable cardinals are bounded below it and another inner model $W$ with a strongly compact cardinal $\kappa$, such that $H_{\kappa^+}^V\subseteq HOD^W$. Similar facts hold for supercompact, measurable and strongly Ramsey cardinals. If a cardinal is supercompact up to a weakly iterable cardinal, then there is an inner model of the Proper Forcing Axiom and another inner model with a supercompact cardinal in which GCH+V=HOD holds. Under the same hypothesis, there is an inner model with level by level equivalence between strong compactness and supercompactness, and indeed, another in which there is level by level inequivalence between strong compactness and supercompactness. If a cardinal is strongly compact up to a weakly iterable cardinal, then there is an inner model in which the least measurable cardinal is strongly compact. If there is a weakly iterable limit $\delta$ of ${\lt}\delta$-supercompact cardinals, then there is an inner model with a proper class of Laver-indestructible supercompact cardinals. We describe three general proof methods, which can be used to prove many similar results.

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