Strongly unfoldable cardinals made indestructible

نویسنده

  • Thomas A. Johnstone
چکیده

Strongly Unfoldable Cardinals Made Indestructible by Thomas A. Johnstone Advisor: Joel David Hamkins I provide indestructibility results for weakly compact, indescribable and strongly unfoldable cardinals. In order to make these large cardinals indestructible, I assume the existence of a strongly unfoldable cardinal κ, which is a hypothesis consistent with V = L. The main result shows that any strongly unfoldable cardinal κ can be made indestructible by all <κ-closed forcing which does not collapse κ. As strongly unfoldable cardinals strengthen both indescribable and weakly compact cardinals, I obtain indestructibility for these cardinals also, thereby reducing the large cardinal hypothesis of previously known indestructibility results for these cardinals significantly. Finally, I use the developed methods to show the consistency of a weakening of the Proper Forcing Axiom PFA relative to the existence of a strongly unfoldable cardinal.

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عنوان ژورنال:
  • J. Symb. Log.

دوره 73  شماره 

صفحات  -

تاریخ انتشار 2008