Laver indestructibility and the class of compact cardinals

被引:27
|
作者
Apter, AW [1 ]
机构
[1] CUNY Bernard M Baruch Coll, Dept Math, New York, NY 10010 USA
关键词
D O I
10.2307/2586593
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Using an idea developed in joint work with Shelah, we show how to redefine Laver's notion of forcing making a supercompact cardinal kappa indestructible under kappa-directed closed forcing to give a new proof of the Kimchi-Magidor Theorem in which every compact cardinal in the universe (supercompact or strongly compact) satisfies certain indestructibility properties. Specifically, we show that if K is the class of supercompact cardinals in the ground model, then it is possible to force and construct a generic extension in which the only strongly compact cardinals are the elements of K or their measurable limit points, every kappa is an element of K is a supercompact cardinal indestructible under kappa-directed closed forcing, and every kappa a measurable limit point of K is a strongly compact cardinal indestructible under kappa-directed closed forcing not changing rho(kappa). We then derive as a corollary a model for the existence of a strongly compact cardinal kappa which is not kappa(+) supercompact but which is indestructible under kappa-directed closed forcing not changing rho(kappa) and remains non-kappa(+) supercompact after such a forcing has been done.
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页码:149 / 157
页数:9
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