{"title":"Strongly unfoldable, splitting and bounding","authors":"Ömer Faruk Bağ, Vera Fischer","doi":"10.1002/malq.202200003","DOIUrl":null,"url":null,"abstract":"<p>Assuming <math>\n <semantics>\n <mi>GCH</mi>\n <annotation>$\\mathsf {GCH}$</annotation>\n </semantics></math>, we show that generalized eventually narrow sequences on a strongly inaccessible cardinal κ are preserved under a one step iteration of the Hechler forcing for adding a dominating κ-real. Moreover, we show that if κ is strongly unfoldable, <math>\n <semantics>\n <mrow>\n <msup>\n <mn>2</mn>\n <mi>κ</mi>\n </msup>\n <mo>=</mo>\n <msup>\n <mi>κ</mi>\n <mo>+</mo>\n </msup>\n </mrow>\n <annotation>$2^\\kappa =\\kappa ^+$</annotation>\n </semantics></math> and λ is a regular cardinal such that <math>\n <semantics>\n <mrow>\n <msup>\n <mi>κ</mi>\n <mo>+</mo>\n </msup>\n <mo><</mo>\n <mi>λ</mi>\n </mrow>\n <annotation>$\\kappa ^+ < \\lambda$</annotation>\n </semantics></math>, then there is a set generic extension in which <math>\n <semantics>\n <mrow>\n <mi>s</mi>\n <mrow>\n <mo>(</mo>\n <mi>κ</mi>\n <mo>)</mo>\n </mrow>\n <mo>=</mo>\n <msup>\n <mi>κ</mi>\n <mo>+</mo>\n </msup>\n <mo><</mo>\n <mi>b</mi>\n <mrow>\n <mo>(</mo>\n <mi>κ</mi>\n <mo>)</mo>\n </mrow>\n <mo>=</mo>\n <mi>c</mi>\n <mrow>\n <mo>(</mo>\n <mi>κ</mi>\n <mo>)</mo>\n </mrow>\n <mo>=</mo>\n <mi>λ</mi>\n </mrow>\n <annotation>$\\mathfrak {s}(\\kappa ) = \\kappa ^+ < \\mathfrak {b}(\\kappa ) = \\mathfrak {c}(\\kappa ) = \\lambda$</annotation>\n </semantics></math>.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"69 1","pages":"7-14"},"PeriodicalIF":0.4000,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/malq.202200003","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Logic Quarterly","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.202200003","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"LOGIC","Score":null,"Total":0}
引用次数: 0
Abstract
Assuming , we show that generalized eventually narrow sequences on a strongly inaccessible cardinal κ are preserved under a one step iteration of the Hechler forcing for adding a dominating κ-real. Moreover, we show that if κ is strongly unfoldable, and λ is a regular cardinal such that , then there is a set generic extension in which .
期刊介绍:
Mathematical Logic Quarterly publishes original contributions on mathematical logic and foundations of mathematics and related areas, such as general logic, model theory, recursion theory, set theory, proof theory and constructive mathematics, algebraic logic, nonstandard models, and logical aspects of theoretical computer science.