{"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":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/malq.202100019","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","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.