{ "id": "1611.08289", "version": "v1", "published": "2016-11-24T19:18:16.000Z", "updated": "2016-11-24T19:18:16.000Z", "title": "Categorical properties on the hyperspace of nontrivial convergent sequences", "authors": [ "S. Garcia-Ferreira", "R. Rojas-Hernandez", "Y. F. Ortiz-Castillo" ], "categories": [ "math.GN" ], "abstract": "In this paper, we shall study categorial properties of the hyperspace of all nontrivial convergent sequences $\\mathcal{S}_c(X)$ of a Fre\\'ech-Urysohn space $X$, this hyperspace is equipped with the Vietoris topology. We mainly prove that $\\mathcal{S}_c(X)$ is meager whenever $X$ is a crowded space, as a corollary we obtain that if $\\mathcal{S}_c(X)$ is Baire, the $X$ has a dense subset of isolated points. As an interesting example $\\mathcal{S}_c(\\omega_1)$ has the Baire property, where $\\omega_1$ carries the order topology (this answers a question from \\cite{sal-yas}). We can give more examples like this one by proving that the Alexandroff duplicated $\\mathcal{A}(Z)$ of a space $Z$ satisfies that $\\mathcal{S}_c(\\mathcal{A}(Z))$ has the Baire property, whenever $Z$ is a $\\Sigma$-product of completely metrizable spaces and $Z$ is crowded. Also we show that if $\\mathcal{S}_c(X)$ is pseudocompact, then $X$ has a relatively countably compact dense subset of isolated points, every finite power of $X$ is pseudocompact, and every $G_\\delta$-point in $X$ must be isolated. We also establish several topological properties of the hyperspace of nontrivial convergent sequences of countable Fre\\'ech-Urysohn spaces with only one non-isolated point.", "revisions": [ { "version": "v1", "updated": "2016-11-24T19:18:16.000Z" } ], "analyses": { "keywords": [ "nontrivial convergent sequences", "categorical properties", "hyperspace", "freech-urysohn space", "baire property" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }