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Related papers: Computability on quasi-Polish spaces

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We will characterise robust monetary utility functions defined on the space of real valued (bounded) continuous functions on a Polish space.

Probability · Mathematics 2022-09-20 Freddy Delbaen

The main result is the following. Let $f \colon X \rightarrow Y$ be a continuous mapping of a completely Baire space $X$ onto a hereditary weakly Preiss-Simon regular space $Y$ such that the image of every open subset of $X$ is a resolvable…

General Topology · Mathematics 2022-08-12 Sergey Medvedev

A topological space $X$ is called Piotrowski if every quasicontinuous map $f:Z\to X$ from a Baire space $Z$ to $X$ has a continuity point. In this paper we survey known results on Piotrowski spaces and investigate the relation of Piotrowski…

General Topology · Mathematics 2021-11-01 Taras Banakh

We investigate the properties of ideals associated with Kuratowski partitions of non-complete Baire metric spaces. We show that such an ideal can be precipitous.

Logic · Mathematics 2020-03-31 Ryszard Frankiewicz , Joanna Jureczko

In the presence of suitable power spaces, compactness of $\mathbf{X}$ can be characterized as the singleton $\{X\}$ being open in the space $\mathcal{O}(\mathbf{X})$ of open subsets of $\mathbf{X}$. Equivalently, this means that universal…

General Topology · Mathematics 2017-01-19 Matthew de Brecht , Arno Pauly

The aim of this paper is to extend the external characterization of I-favorable spaces. This allows us to obtain a characterization of compact I-favorable spaces in terms of quasi k-metrics. We also provide proofs of some author's results…

General Topology · Mathematics 2018-01-23 Vesko Valov

The space of unitary $C_{0}$-semigroups on separable infinite dimensional Hilbert space, when viewed under the topology of uniform weak convergence on compact subsets of $\mathbb{R}_{+}$, is known to admit various interesting residual…

Functional Analysis · Mathematics 2023-02-02 Raj Dahya

We investigate different notions of "computable topological base" for represented spaces. We show that several non-equivalent notions of bases become equivalent when we consider computably enumerable bases. This indicates the existence of a…

Logic · Mathematics 2025-09-25 Vasco Brattka , Emmanuel Rauzy

An \'{e}tale space over a topological space $Y$ is defined as a local homeomorphism from a topological space $X$ into $Y$. They often come up in topos theory because of the equivalence between sheaves and \'{e}tale spaces over a space. In…

Logic · Mathematics 2026-05-01 Matthew de Brecht

While there is a well-established notion of what a computable ordinal is, the question which functions on the countable ordinals ought to be computable has received less attention so far. We propose a notion of computability on the space of…

Logic in Computer Science · Computer Science 2017-04-11 Arno Pauly

We study the algorithmic content of Pontryagin - van Kampen duality. We prove that the dualization is computable in the important cases of compact and locally compact totally disconnected Polish abelian groups. The applications of our main…

Logic · Mathematics 2021-08-24 Martino Lupini , Alexander Melnikov , Andre Nies

We study spaces that can be mapped onto the Baire space (i.e. the countable power of the countable discrete space) by a continuous quasi-open bijection. We give a characterization of such spaces in terms of Souslin schemes and call these…

General Topology · Mathematics 2022-08-15 Mikhail Patrakeev , Vlad Smolin

We obtain several game characterizations of Baire 1 functions between Polish spaces X, Y which extends the recent result of V. Kiss. Then we propose similar characterizations for equi-Bare 1 families of functions. Also, using related ideas,…

General Topology · Mathematics 2024-04-12 Marek Balcerzak , Tomasz Natkaniec , Piotr Szuca

In this paper we present a few properties of $K$-partitions, which are partitions of Baire spaces such that all subfamilies of such a partition sum to a set with the Baire property. Among the result proven we have general existence result…

Logic · Mathematics 2022-05-26 Sławomir Kusiński

We characterize coset spaces of topological groups which are coset spaces of (separable) metrizable groups and complete metrizable (Polish) groups. Besides, it is shown that for a $G$-space $X$ with a $d$-open action there is a topological…

General Topology · Mathematics 2017-11-29 Sergey Antonyan , Natella Antonyan , Konstantin Kozlov

We begin to study classical dimension theory from the computable analysis (TTE) point of view. For computable metric spaces, several effectivisations of zero-dimensionality are shown to be equivalent. The part of this characterisation that…

Logic · Mathematics 2015-07-01 Robert Kenny

We revisit the definition of effective local compactness, and propose an approach that works for arbitrary countably-based spaces extending the previous work on computable metric spaces. We use this to show that effective local compactness…

Logic in Computer Science · Computer Science 2019-03-14 Arno Pauly

We investigate what it means for a (Hausdorff, second-countable) topological group to be computable. We compare several potential definitions in the literature. We relate these notions with the well-established definitions of effective…

Logic · Mathematics 2025-04-16 Heer Tern Koh , Alexander Melnikov , Keng Meng Ng

We prove that for each Polish space X, the space C(X) of continuous real-valued functions on X satisfies a strong version of the Pytkeev property, if endowed with the compact-open topology. (This shows that whereas it need not be…

General Topology · Mathematics 2010-11-05 Boaz Tsaban , Lyubomyr Zdomskyy

We prove some consistency results concerning the Moving Off Property for locally compact spaces and thus the question of whether their function spaces are Baire.

General Topology · Mathematics 2015-07-27 Franklin D. Tall