当前位置: X-MOL 学术Ann. Pure Appl. Logic › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Perfect tree forcings for singular cardinals
Annals of Pure and Applied Logic ( IF 0.8 ) Pub Date : 2020-05-13 , DOI: 10.1016/j.apal.2020.102827
Natasha Dobrinen , Dan Hathaway , Karel Prikry

We investigate forcing properties of perfect tree forcings defined by Prikry to answer a question of Solovay in the late 1960's regarding first failures of distributivity. Given a strictly increasing sequence of regular cardinals κn:n<ω, Prikry defined the forcing P of all perfect subtrees of n<ωκn, and proved that for κ=supn<ωκn, assuming the necessary cardinal arithmetic, the Boolean completion B of P is (ω,μ)-distributive for all μ<κ but (ω,κ,δ)-distributivity fails for all δ<κ, implying failure of the (ω,κ)-d.l. These hitherto unpublished results are included, setting the stage for the following recent results. P satisfies a Sacks-type property, implying that B is (ω,,<κ)-distributive. The (h,2)-d.l. and the (d,,<κ)-d.l. fail in B. P(ω)/fin completely embeds into B. Also, B collapses κω to h. We further prove that if κ is a limit of countably many measurable cardinals, then B adds a minimal degree of constructibility for new ω-sequences. Some of these results generalize to cardinals κ with uncountable cofinality.



中文翻译:

单数主教的完美树强迫

我们调查了由Prikry定义的完美树强迫的强迫属性,以回答Solovay在1960年代后期有关首次分配失败的问题。鉴于常规红衣主教严格增加了顺序κññ<ω,Prikry定义了强制 P 的所有完美子树 ñ<ωκñ,并证明 κ=SUPñ<ωκñ,假设必要的基本算术,则布尔完成 Pωμ-为所有人分配 μ<κωκδ-所有人的分配失败 δ<κ,表示失败 ωκ-dl包括了这些迄今尚未发布的结果,为以下最近的结果奠定了基础。 P 满足Sacks类型的属性,这意味着 ω<κ-分布。的H2-dl和 d<κ-dl失败 Pω/ 完全嵌入 。也, 崩溃 κωH。我们进一步证明,如果κ是许多可测量基数的极限,则为新的ω序列增加了最小程度的可构造性。其中一些结果普遍适用于具有不可数最终确定性的红衣主教κ

更新日期:2020-05-13
down
wechat
bug