{"title":"On the Ramsey numbers of daisies I","authors":"Pavel Pudlák, Vojtech Rödl, Marcelo Sales","doi":"10.1017/s0963548324000221","DOIUrl":null,"url":null,"abstract":"Daisies are a special type of hypergraph introduced by Bollobás, Leader and Malvenuto. An <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline1.png\"/> <jats:tex-math> $r$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-daisy determined by a pair of disjoint sets <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline2.png\"/> <jats:tex-math> $K$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline3.png\"/> <jats:tex-math> $M$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is the <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline4.png\"/> <jats:tex-math> $(r+|K|)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-uniform hypergraph <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline5.png\"/> <jats:tex-math> $\\{K\\cup P\\,{:}\\, P\\in M^{(r)}\\}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. Bollobás, Leader and Malvenuto initiated the study of Turán type density problems for daisies. This paper deals with Ramsey numbers of daisies, which are natural generalisations of classical Ramsey numbers. We discuss upper and lower bounds for the Ramsey number of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0963548324000221_inline6.png\"/> <jats:tex-math> $r$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>-daisies and also for special cases where the size of the kernel is bounded.","PeriodicalId":10503,"journal":{"name":"Combinatorics, Probability and Computing","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Combinatorics, Probability and Computing","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1017/s0963548324000221","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
Daisies are a special type of hypergraph introduced by Bollobás, Leader and Malvenuto. An $r$ -daisy determined by a pair of disjoint sets $K$ and $M$ is the $(r+|K|)$ -uniform hypergraph $\{K\cup P\,{:}\, P\in M^{(r)}\}$ . Bollobás, Leader and Malvenuto initiated the study of Turán type density problems for daisies. This paper deals with Ramsey numbers of daisies, which are natural generalisations of classical Ramsey numbers. We discuss upper and lower bounds for the Ramsey number of $r$ -daisies and also for special cases where the size of the kernel is bounded.