WEAKLY REMARKABLE CARDINALS, ERDAOS CARDINALS, and the GENERIC VOPĚNKA PRINCIPLE

We consider a weak version of Schindler's remarkable cardinals that may fail to be Σ2 - reflecting. We show that the Σ2-reflecting weakly remarkable cardinals are exactly the remarkable cardinals, and that the existence of a non-Σ2 -reflecting weakly remarkable cardinal has higher consistency s...

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Bibliographic Details
Main Author: Wilson, T.M (Author)
Format: Article
Language:English
Published: Cambridge University Press 2019
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Online Access:View Fulltext in Publisher
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Summary:We consider a weak version of Schindler's remarkable cardinals that may fail to be Σ2 - reflecting. We show that the Σ2-reflecting weakly remarkable cardinals are exactly the remarkable cardinals, and that the existence of a non-Σ2 -reflecting weakly remarkable cardinal has higher consistency strength: it is equiconsistent with the existence of an ω-Erdos cardinal. We give an application involving gVP, the generic Vopěnka principle defined by Bagaria, Gitman, and Schindler. Namely, we show that gVP + "Ord is not Δ2-Mahlo" and gVP(Π1) + "there is no proper class of remarkable cardinals" are both equiconsistent with the existence of a proper class of ω-Erdos cardinals, extending results of Bagaria, Gitman, Hamkins, and Schindler. Copyright © 2019 The Association for Symbolic Logic.
ISBN:00224812 (ISSN)
DOI:10.1017/jsl.2018.76