中文
相关论文

相关论文: Classification of selectors for sequences of dense…

200 篇论文

We give the characteristics of selectors for sequences of dense sets of Cp(X) through the selection principles of a Tychonoff space X.

一般拓扑 · 数学 2017-11-08 Alexander V. Osipov

For a Tychonoff space $X$, we will denote by $USC_{p}(X)$ ($B_1(X)$) a set of all real-valued upper semicontinuous functions (a set of all Baire functions of class 1) defined on $X$ endowed with the pointwise convergence topology. In this…

一般拓扑 · 数学 2018-09-27 Alexander V. Osipov , Evgenii G. Pytkeev

A topological space $X$ is Baire if the Baire Category Theorem holds for $X$, i.e., the intersection of any sequence of open dense subsets of $X$ is dense in $X$. One of the interesting problems for the space $B_1(X)$ of all Baire-one…

一般拓扑 · 数学 2024-11-05 Alexander V. Osipov

In this paper, we give necessary and sufficient conditions for the space B_1(X) of first Baire class functions on a Tychonoff space X, with pointwise topology, to be (strongly) sequentially separable.

一般拓扑 · 数学 2016-04-19 Alexander V. Osipov , Evgenii G. Pytkeev

A topological space $X$ is Baire if the intersection of any sequence of open dense subsets of $X$ is dense in $X$. Let $C_p(X,[0,1])$ denote the space of all continuous $[0,1]$-valued functions on a Tychonoff space $X$ with the topology of…

一般拓扑 · 数学 2022-03-14 Alexander V. Osipov , Evgenii G. Pytkeev

A separable space is strongly sequentially separable if, for each countable dense set, every point in the space is a limit of a sequence from the dense set. We consider this and related properties, for the spaces of continous and Borel…

一般拓扑 · 数学 2019-11-11 Alexander V. Osipov , Piotr Szewczak , Boaz Tsaban

A topological space $X$ is Baire if the Baire Category Theorem holds for $X$, i.e., the intersection of any sequence of open dense subsets of $X$ is dense in $X$. In this paper, we have obtained that the space $B^{st}_1(X)$ of pointwise…

一般拓扑 · 数学 2022-06-06 Alexander V. Osipov

We investigate strongly separately continuous functions on a product of topological spaces and prove that if $X$ is a countable product of real lines, then there exists a strongly separately continuous function $f:X\to\mathbb R$ which is…

一般拓扑 · 数学 2015-08-07 Olena Karlova

A topological space $X$ is Baire if the Baire Category Theorem holds for $X$, i.e., the intersection of any sequence of open dense subsets of $X$ is dense in $X$. One of the interesting problems in the theory of functional spaces is the…

一般拓扑 · 数学 2024-09-05 Alexander V. Osipov

For a Tychonoff space $X$, we denote by $C_k(X)$ the space of all real-valued continuous functions on X with the compact-open topology. In this paper, we have gave characterization for $C_k(X)$ to satisfy $S_{fin}(S, S)$.

一般拓扑 · 数学 2018-05-16 Alexander V. Osipov

We investigate the Baire classification of mappings $f:X\times Y\to Z$, where $X$ belongs to a wide class of spaces, which includes all metrizable spaces, $Y$ is a topological space, $Z$ is an equiconnected space, which are continuous in…

一般拓扑 · 数学 2014-07-23 Olena Karlova , Volodymyr Maslyuchenko , Volodymyr Mykhaylyuk

We prove that every homogeneous countable dense homogeneous topological space containing a copy of the Cantor set is a Baire space. In particular, every countable dense homogeneous topological vector space is a Baire space. It follows that,…

一般拓扑 · 数学 2023-09-28 Tadeusz Dobrowolski , Mikołaj Krupski , Witold Marciszewski

We prove the following two results. 1. If $X$ is a completely regular space such that for every topological space $Y$ each separately continuous function $f:X\times Y\to\mathbb R$ is of the first Baire class, then every Lindel\"of subspace…

一般拓扑 · 数学 2016-01-21 V. V. Mykhaylyuk

For a Tychonoff space $X$, we denote by $(C(X), \tau_k, \tau_p)$ the bitopological space of all real-valued continuous functions on $X$ where $\tau_k$ is the compact-open topology and $\tau_p$ is the topology of pointwise convergence. In…

一般拓扑 · 数学 2019-03-21 Daniil Lyakhovets , Alexander V. Osipov

The paper considers the spaces $B_p[1, \alpha]$ of all Baire functions $x\colon [1,\alpha]\to \mathbb{R}$, defined on segments of ordinals $[1,\alpha]$ and endowed with the topology of pointwise convergence. A complete topological…

一般拓扑 · 数学 2018-06-26 L. V. Genze , S. P. Gul'ko , T. E. Khmyleva

For a Tychonoff space $X$, $B_1(X)$ denotes the space of all Baire-one functions on $X$ endowed with the pointwise topology. We prove that the following assertions are equivalent: (1) $B_1(X)$ is a (semi-)Montel space, (2) $B_1(X)$ is a…

一般拓扑 · 数学 2026-01-13 Saak Gabriyelyan , Alexander V. Osipov , Evgenii Reznichenko

The set of continuous or Baire class 1 functions defined on a metric space $X$ is endowed with the natural pointwise partial order. We investigate how the possible lengths of well-ordered monotone sequences (with respect to this order)…

逻辑 · 数学 2011-09-27 Márton Elekes , Kenneth Kunen

A topological space $X$ is Baire if the intersection of any sequence of open dense subsets of $X$ is dense in $X$. One of the interesting problems for the space of Baire functions is the Banakh-Gabriyelyan problem: Let $\alpha$ be a…

一般拓扑 · 数学 2025-03-06 Alexander V. Osipov

Let $USC^*_p(X)$ be the topological space of real upper semicontinuous bounded functions defined on $X$ with the subspace topology of the product topology on ${}^X\mathbb{R}$. $\tilde\Phi^{\uparrow},\tilde\Psi^{\uparrow}$ are the sets of…

一般拓扑 · 数学 2019-07-02 Lev Bukovský , Alexander V. Osipov

For a topological space X, let (RX)s := (RX,Ts) be the cartesian product of |X| copies of the real line R with the topology of the uniform convergence on separable subsets of X. In this article we analyze the subspace C(X) of (RX)s of all…

‹ 上一页 1 2 3 10 下一页 ›