{"title":"传递紧凑性","authors":"Tom Benhamou, Jing Zhang","doi":"10.1112/jlms.12940","DOIUrl":null,"url":null,"abstract":"<p>We demonstrate that the technology of Radin forcing can be used to transfer compactness properties at a weakly inaccessible but not strong limit cardinal to a strongly inaccessible cardinal. As an application, relative to the existence of large cardinals, we construct a model of set theory in which there is a strongly inaccessible cardinal <span></span><math>\n <semantics>\n <mi>κ</mi>\n <annotation>$\\kappa$</annotation>\n </semantics></math> that is <span></span><math>\n <semantics>\n <mi>n</mi>\n <annotation>$n$</annotation>\n </semantics></math>-<span></span><math>\n <semantics>\n <mi>d</mi>\n <annotation>$d$</annotation>\n </semantics></math>-stationary for all <span></span><math>\n <semantics>\n <mrow>\n <mi>n</mi>\n <mo>∈</mo>\n <mi>ω</mi>\n </mrow>\n <annotation>$n\\in \\omega$</annotation>\n </semantics></math> but not weakly compact. This is in sharp contrast to the situation in the constructible universe <span></span><math>\n <semantics>\n <mi>L</mi>\n <annotation>$L$</annotation>\n </semantics></math>, where <span></span><math>\n <semantics>\n <mi>κ</mi>\n <annotation>$\\kappa$</annotation>\n </semantics></math> being <span></span><math>\n <semantics>\n <mrow>\n <mo>(</mo>\n <mi>n</mi>\n <mo>+</mo>\n <mn>1</mn>\n <mo>)</mo>\n </mrow>\n <annotation>$(n+1)$</annotation>\n </semantics></math>-<span></span><math>\n <semantics>\n <mi>d</mi>\n <annotation>$d$</annotation>\n </semantics></math>-stationary is equivalent to <span></span><math>\n <semantics>\n <mi>κ</mi>\n <annotation>$\\kappa$</annotation>\n </semantics></math> being <span></span><math>\n <semantics>\n <msubsup>\n <mi>Π</mi>\n <mi>n</mi>\n <mn>1</mn>\n </msubsup>\n <annotation>$\\mathbf {\\Pi }^1_n$</annotation>\n </semantics></math>-indescribable. We also show that it is consistent that there is a cardinal <span></span><math>\n <semantics>\n <mrow>\n <mi>κ</mi>\n <mo>⩽</mo>\n <msup>\n <mn>2</mn>\n <mi>ω</mi>\n </msup>\n </mrow>\n <annotation>$\\kappa \\leqslant 2^\\omega$</annotation>\n </semantics></math> such that <span></span><math>\n <semantics>\n <mrow>\n <msub>\n <mi>P</mi>\n <mi>κ</mi>\n </msub>\n <mrow>\n <mo>(</mo>\n <mi>λ</mi>\n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation>$P_\\kappa (\\lambda)$</annotation>\n </semantics></math> is <span></span><math>\n <semantics>\n <mi>n</mi>\n <annotation>$n$</annotation>\n </semantics></math>-stationary for all <span></span><math>\n <semantics>\n <mrow>\n <mi>λ</mi>\n <mo>⩾</mo>\n <mi>κ</mi>\n </mrow>\n <annotation>$\\lambda \\geqslant \\kappa$</annotation>\n </semantics></math> and <span></span><math>\n <semantics>\n <mrow>\n <mi>n</mi>\n <mo>∈</mo>\n <mi>ω</mi>\n </mrow>\n <annotation>$n\\in \\omega$</annotation>\n </semantics></math>, answering a question of Sakai.</p>","PeriodicalId":49989,"journal":{"name":"Journal of the London Mathematical Society-Second Series","volume":"109 6","pages":""},"PeriodicalIF":1.4000,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1112/jlms.12940","citationCount":"0","resultStr":"{\"title\":\"Transferring compactness\",\"authors\":\"Tom Benhamou, Jing Zhang\",\"doi\":\"10.1112/jlms.12940\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We demonstrate that the technology of Radin forcing can be used to transfer compactness properties at a weakly inaccessible but not strong limit cardinal to a strongly inaccessible cardinal. As an application, relative to the existence of large cardinals, we construct a model of set theory in which there is a strongly inaccessible cardinal <span></span><math>\\n <semantics>\\n <mi>κ</mi>\\n <annotation>$\\\\kappa$</annotation>\\n </semantics></math> that is <span></span><math>\\n <semantics>\\n <mi>n</mi>\\n <annotation>$n$</annotation>\\n </semantics></math>-<span></span><math>\\n <semantics>\\n <mi>d</mi>\\n <annotation>$d$</annotation>\\n </semantics></math>-stationary for all <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>n</mi>\\n <mo>∈</mo>\\n <mi>ω</mi>\\n </mrow>\\n <annotation>$n\\\\in \\\\omega$</annotation>\\n </semantics></math> but not weakly compact. This is in sharp contrast to the situation in the constructible universe <span></span><math>\\n <semantics>\\n <mi>L</mi>\\n <annotation>$L$</annotation>\\n </semantics></math>, where <span></span><math>\\n <semantics>\\n <mi>κ</mi>\\n <annotation>$\\\\kappa$</annotation>\\n </semantics></math> being <span></span><math>\\n <semantics>\\n <mrow>\\n <mo>(</mo>\\n <mi>n</mi>\\n <mo>+</mo>\\n <mn>1</mn>\\n <mo>)</mo>\\n </mrow>\\n <annotation>$(n+1)$</annotation>\\n </semantics></math>-<span></span><math>\\n <semantics>\\n <mi>d</mi>\\n <annotation>$d$</annotation>\\n </semantics></math>-stationary is equivalent to <span></span><math>\\n <semantics>\\n <mi>κ</mi>\\n <annotation>$\\\\kappa$</annotation>\\n </semantics></math> being <span></span><math>\\n <semantics>\\n <msubsup>\\n <mi>Π</mi>\\n <mi>n</mi>\\n <mn>1</mn>\\n </msubsup>\\n <annotation>$\\\\mathbf {\\\\Pi }^1_n$</annotation>\\n </semantics></math>-indescribable. We also show that it is consistent that there is a cardinal <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>κ</mi>\\n <mo>⩽</mo>\\n <msup>\\n <mn>2</mn>\\n <mi>ω</mi>\\n </msup>\\n </mrow>\\n <annotation>$\\\\kappa \\\\leqslant 2^\\\\omega$</annotation>\\n </semantics></math> such that <span></span><math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>P</mi>\\n <mi>κ</mi>\\n </msub>\\n <mrow>\\n <mo>(</mo>\\n <mi>λ</mi>\\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation>$P_\\\\kappa (\\\\lambda)$</annotation>\\n </semantics></math> is <span></span><math>\\n <semantics>\\n <mi>n</mi>\\n <annotation>$n$</annotation>\\n </semantics></math>-stationary for all <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>λ</mi>\\n <mo>⩾</mo>\\n <mi>κ</mi>\\n </mrow>\\n <annotation>$\\\\lambda \\\\geqslant \\\\kappa$</annotation>\\n </semantics></math> and <span></span><math>\\n <semantics>\\n <mrow>\\n <mi>n</mi>\\n <mo>∈</mo>\\n <mi>ω</mi>\\n </mrow>\\n <annotation>$n\\\\in \\\\omega$</annotation>\\n </semantics></math>, answering a question of Sakai.</p>\",\"PeriodicalId\":49989,\"journal\":{\"name\":\"Journal of the London Mathematical Society-Second Series\",\"volume\":\"109 6\",\"pages\":\"\"},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2024-05-30\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1112/jlms.12940\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of the London Mathematical Society-Second Series\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/jlms.12940\",\"RegionNum\":2,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the London Mathematical Society-Second Series","FirstCategoryId":"100","ListUrlMain":"https://londmathsoc.onlinelibrary.wiley.com/doi/10.1112/jlms.12940","RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
摘要
我们证明,拉丁强迫技术可以用来把弱不可及但非强极限红心的紧凑性转移到强不可及红心。作为一个应用,相对于大红心的存在,我们构建了一个集合论模型,其中存在一个强不可及红心κ\ $kappa$,对于所有n∈ω\ $n\ in \omega$来说,它是n $n$ - d $d$-稳态的,但不是弱紧凑的。这与可构造宇宙 L $L$ 中的情况形成鲜明对比,在可构造宇宙 L $L$ 中,κ $kappa$ 是 ( n + 1 ) $(n+1)$ - d $d$ - 稳定的等价于 κ $kappa$ 是 Π n 1 $mathbf\ {Pi }^1_n$ - 不可描述的。我们还证明了,对于所有 λ ⩾ κ\ $lambda \geqslant \kappa$ 和 n∈ ω $n\in \omega$ 而言,存在一个红心数 κ ⩽ 2 ω $\kappa \leqslant 2^\omega$ 使得 P κ ( λ ) $P_\kappa (\lambda)$ 是 n $n$ - 稳定的,这一点是一致的,回答了 Sakai 的一个问题。
We demonstrate that the technology of Radin forcing can be used to transfer compactness properties at a weakly inaccessible but not strong limit cardinal to a strongly inaccessible cardinal. As an application, relative to the existence of large cardinals, we construct a model of set theory in which there is a strongly inaccessible cardinal that is --stationary for all but not weakly compact. This is in sharp contrast to the situation in the constructible universe , where being --stationary is equivalent to being -indescribable. We also show that it is consistent that there is a cardinal such that is -stationary for all and , answering a question of Sakai.
期刊介绍:
The Journal of the London Mathematical Society has been publishing leading research in a broad range of mathematical subject areas since 1926. The Journal welcomes papers on subjects of general interest that represent a significant advance in mathematical knowledge, as well as submissions that are deemed to stimulate new interest and research activity.