{"title":"A note on edge colorings and trees","authors":"Adi Jarden, Ziv Shami","doi":"10.1002/malq.202100019","DOIUrl":null,"url":null,"abstract":"<p>We point out some connections between existence of homogenous sets for certain edge colorings and existence of branches in certain trees. As a consequence, we get that any locally additive coloring (a notion introduced in the paper) of a cardinal κ has a homogeneous set of size κ provided that the number of colors μ satisfies <math>\n <semantics>\n <mrow>\n <msup>\n <mi>μ</mi>\n <mo>+</mo>\n </msup>\n <mo><</mo>\n <mi>κ</mi>\n </mrow>\n <annotation>$\\mu ^+<\\kappa$</annotation>\n </semantics></math>. Another result is that an uncountable cardinal κ is weakly compact if and only if κ is regular, has the tree property, and for each <math>\n <semantics>\n <mrow>\n <mi>λ</mi>\n <mo>,</mo>\n <mi>μ</mi>\n <mo><</mo>\n <mi>κ</mi>\n </mrow>\n <annotation>$\\lambda ,\\mu <\\kappa$</annotation>\n </semantics></math> there exists <math>\n <semantics>\n <mrow>\n <msup>\n <mi>κ</mi>\n <mo>∗</mo>\n </msup>\n <mo><</mo>\n <mi>κ</mi>\n </mrow>\n <annotation>$\\kappa ^*<\\kappa$</annotation>\n </semantics></math> such that every tree of height μ with λ nodes has less than <math>\n <semantics>\n <msup>\n <mi>κ</mi>\n <mo>∗</mo>\n </msup>\n <annotation>$\\kappa ^*$</annotation>\n </semantics></math> branches.</p>","PeriodicalId":49864,"journal":{"name":"Mathematical Logic Quarterly","volume":"68 4","pages":"447-457"},"PeriodicalIF":0.4000,"publicationDate":"2022-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Logic Quarterly","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.202100019","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
We point out some connections between existence of homogenous sets for certain edge colorings and existence of branches in certain trees. As a consequence, we get that any locally additive coloring (a notion introduced in the paper) of a cardinal κ has a homogeneous set of size κ provided that the number of colors μ satisfies . Another result is that an uncountable cardinal κ is weakly compact if and only if κ is regular, has the tree property, and for each there exists such that every tree of height μ with λ nodes has less than branches.
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.