{"title":"Irreducibility of strong size levels","authors":"Alejandro Illanes, Verónica Martínez-de-la-Vega","doi":"10.1515/ms-2024-0039","DOIUrl":null,"url":null,"abstract":"Given a continuum <jats:italic>X</jats:italic>, <jats:italic>C<jats:sub>n</jats:sub> </jats:italic>(<jats:italic>X</jats:italic>) denotes the hyperspace of nonempty closed subsets of <jats:italic>X</jats:italic> with at most <jats:italic>n</jats:italic> components. A strong size level is a subset of the form <jats:italic>σ</jats:italic> <jats:sup>−1</jats:sup>(<jats:italic>t</jats:italic>), where <jats:italic>σ</jats:italic> is a strong size map for <jats:italic>C<jats:sub>n</jats:sub> </jats:italic>(<jats:italic>X</jats:italic>) and <jats:italic>t</jats:italic> ∈ (0, 1]. In this paper, answering a question by Capulín-Pérez, Fuentes-Montes de Oca, Lara-Mejía and Orozco-Zitli, we prove that for each <jats:italic>n</jats:italic> ≥ 2, no strong size level for <jats:italic>C<jats:sub>n</jats:sub> </jats:italic>(<jats:italic>X</jats:italic>) is irreducible.","PeriodicalId":18282,"journal":{"name":"Mathematica Slovaca","volume":"63 1","pages":""},"PeriodicalIF":0.9000,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematica Slovaca","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1515/ms-2024-0039","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Given a continuum X, Cn(X) denotes the hyperspace of nonempty closed subsets of X with at most n components. A strong size level is a subset of the form σ−1(t), where σ is a strong size map for Cn(X) and t ∈ (0, 1]. In this paper, answering a question by Capulín-Pérez, Fuentes-Montes de Oca, Lara-Mejía and Orozco-Zitli, we prove that for each n ≥ 2, no strong size level for Cn(X) is irreducible.
期刊介绍:
Mathematica Slovaca, the oldest and best mathematical journal in Slovakia, was founded in 1951 at the Mathematical Institute of the Slovak Academy of Science, Bratislava. It covers practically all mathematical areas. As a respectful international mathematical journal, it publishes only highly nontrivial original articles with complete proofs by assuring a high quality reviewing process. Its reputation was approved by many outstanding mathematicians who already contributed to Math. Slovaca. It makes bridges among mathematics, physics, soft computing, cryptography, biology, economy, measuring, etc. The Journal publishes original articles with complete proofs. Besides short notes the journal publishes also surveys as well as some issues are focusing on a theme of current interest.