{ "id": "2004.02013", "version": "v1", "published": "2020-04-04T20:43:57.000Z", "updated": "2020-04-04T20:43:57.000Z", "title": "Games and hereditary Baireness in hyperspaces and spaces of probability measures", "authors": [ "MikoĊ‚aj Krupski" ], "categories": [ "math.GN" ], "abstract": "We establish that the existence of a winning strategy in certain topological games, closely related to a strong game of Choquet, played in a topological space $X$ and its hyperspace $K(X)$ of all nonempty compact subsets of $X$ equipped with the Vietoris topology, is equivalent for one of the players. For a separable metrizable space $X$, we identify a game-theoretic condition equivalent to $K(X)$ being hereditarily Baire. It implies quite easily a recent result of Gartside, Medini and Zdomskyy that characterizes hereditary Baire property of hyperspaces $K(X)$ over separable metrizable spaces $X$ via the Menger property of the remainder of a compactification of $X$. Subsequently, we use topological games to study hereditary Baire property in spaces of probability measures and in hyperspaces over filters on natural numbers. To this end, we introduce a notion of strong $P$-filter $\\mathcal{F}$ and prove that it is equivalent to $K(\\mathcal{F})$ being hereditarily Baire. We also show that if $X$ is separable metrizable and $K(X)$ is hereditarily Baire, then the space $P_r(X)$ of Borel probability Radon measures on $X$ is hereditarily Baire too. It follows that there exists (in ZFC) a separable metrizable space $X$ which is not completely metrizable with $P_r(X)$ hereditarily Baire. As far as we know this is the first example of this kind.", "revisions": [ { "version": "v1", "updated": "2020-04-04T20:43:57.000Z" } ], "analyses": { "subjects": [ "54B20", "54E52", "60B05", "91A44", "54D40", "54D20", "54D80" ], "keywords": [ "probability measures", "hereditarily baire", "hereditary baireness", "separable metrizable space", "hyperspace" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }