{"title":"The hyperspace of k-dimensional closed convex sets","authors":"Adriana Escobedo-Bustamante , Natalia Jonard-Pérez","doi":"10.1016/j.topol.2024.109154","DOIUrl":null,"url":null,"abstract":"<div><div>For every <span><math><mi>n</mi><mo>≥</mo><mn>2</mn></math></span>, let <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> denote the hyperspace of all <em>k</em>-dimensional closed convex subsets of the Euclidean space <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>n</mi></mrow></msup></math></span> endowed with the Atouch-Wets topology. Let <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi><mo>,</mo><mi>b</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> be the subset of <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> consisting of all <em>k</em>-dimensional compact convex subsets. In this paper we explore the topology of <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi><mo>,</mo><mi>b</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> and the relation of these hyperspaces with the Grassmann manifold <span><math><msub><mrow><mi>G</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span>. We prove that both <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> and <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi><mo>,</mo><mi>b</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> are Hilbert cube manifolds with a fiber bundle structure over <span><math><msub><mrow><mi>G</mi></mrow><mrow><mi>k</mi></mrow></msub><mo>(</mo><mi>n</mi><mo>)</mo></math></span>. We also show that the fiber of <span><math><msubsup><mrow><mi>K</mi></mrow><mrow><mi>k</mi><mo>,</mo><mi>b</mi></mrow><mrow><mi>n</mi></mrow></msubsup></math></span> with respect to this fiber bundle structure is homeomorphic with <span><math><msup><mrow><mi>R</mi></mrow><mrow><mfrac><mrow><mi>k</mi><mo>(</mo><mi>k</mi><mo>+</mo><mn>1</mn><mo>)</mo><mo>+</mo><mn>2</mn><mi>n</mi></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></msup><mo>×</mo><mi>Q</mi></math></span>, where <em>Q</em> stands for the Hilbert cube.</div></div>","PeriodicalId":51201,"journal":{"name":"Topology and its Applications","volume":"360 ","pages":"Article 109154"},"PeriodicalIF":0.6000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Topology and its Applications","FirstCategoryId":"100","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0166864124003390","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
For every , let denote the hyperspace of all k-dimensional closed convex subsets of the Euclidean space endowed with the Atouch-Wets topology. Let be the subset of consisting of all k-dimensional compact convex subsets. In this paper we explore the topology of and and the relation of these hyperspaces with the Grassmann manifold . We prove that both and are Hilbert cube manifolds with a fiber bundle structure over . We also show that the fiber of with respect to this fiber bundle structure is homeomorphic with , where Q stands for the Hilbert cube.
期刊介绍:
Topology and its Applications is primarily concerned with publishing original research papers of moderate length. However, a limited number of carefully selected survey or expository papers are also included. The mathematical focus of the journal is that suggested by the title: Research in Topology. It is felt that it is inadvisable to attempt a definitive description of topology as understood for this journal. Certainly the subject includes the algebraic, general, geometric, and set-theoretic facets of topology as well as areas of interactions between topology and other mathematical disciplines, e.g. topological algebra, topological dynamics, functional analysis, category theory. Since the roles of various aspects of topology continue to change, the non-specific delineation of topics serves to reflect the current state of research in topology.
At regular intervals, the journal publishes a section entitled Open Problems in Topology, edited by J. van Mill and G.M. Reed. This is a status report on the 1100 problems listed in the book of the same name published by North-Holland in 1990, edited by van Mill and Reed.