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Related papers: Extending Baire-one functions on compact spaces

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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…

General Topology · Mathematics 2024-09-05 Alexander V. Osipov

In this article, we continue our study of Baire one functions on a topological space $X$, denoted by $B_1(X)$ and extend the well known M. H. Stones's theorem from $C(X)$ to $B_1(X)$. Introducing the structure space of $B_1(X)$, it is…

General Topology · Mathematics 2022-01-10 A. Deb Ray , Atanu Mondal

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…

General Topology · Mathematics 2024-11-05 Alexander V. Osipov

Let $X$ and $Y$ be Banach or normed linear spaces and $F\subset X$ a closed set. We apply our recent extension theorem for vector-valued Baire one functions arXiv:1512.03717 to obtain an extension theorem for vector-valued functions…

Classical Analysis and ODEs · Mathematics 2017-01-24 Martin Koc , Jan Kolář

We introduce the notion of $B_1$-retract and investigate the connection between $B_1$- and $H_1$-retracts.

General Topology · Mathematics 2014-07-22 Olena Karlova

We investigate the possibility of extension of $F_\sigma$-measurable and Baire-one maps from subspaces of topological spaces when these maps take values in spaces which covers by a sequence of metrizable spaces with special properties

General Topology · Mathematics 2018-05-11 Olena Karlova , Volodymyr Mykhaylyuk

It is solved the problem on construction of separately continuous functions on product of $n$ topological spaces with given restriction. In particular, it is shown that for every topological space $X$ and $n-1$ Baire class function $g:X\to…

General Topology · Mathematics 2016-02-02 V. V. Mykhaylyuk

Given a function $f : A \to \mathbb{R}^n$ of a certain regularity defined on some open subset $A \subseteq \mathbb{R}^m$, it is a classical problem of analysis to investigate whether the function can be extended to all of $\mathbb{R}^m$ in…

General Relativity and Quantum Cosmology · Physics 2024-08-22 Jan Sbierski

We answer two questions from {\it V.Bykov, On Baire class one functions on a product space, Topol. Appl. {199} (2016) 55--62,} and prove that every Baire one function on a subspace of a countable perfectly normal product is the pointwise…

General Topology · Mathematics 2016-03-03 Olena Karlova , Volodymyr Mykhaylyuk

It is solved the problem on constructed of separately continuous functions on product of two topological spaces with given restriction. In particular, it is shown that for every topological space $X$ and first Baire class function $g:X\to…

General Topology · Mathematics 2016-02-01 V. V. Mykhaylyuk

A compact space $X$ is called $\pi$-monolithic if for any surjective continuous mapping $f:X\rightarrow K$ where $K$ is a metrizable compact space there exists a metrizable compact space $T\subseteq X$ such that $f(T)=K$. A topological…

General Topology · Mathematics 2022-08-04 Alexander V. Osipov , Evgenii G. Pytkeev

We consider Bergman spaces and variations of them in one or several complex variables. For some domains we show that in these spaces the generic function is totally unbounded and hence non - extendable. We also show that the generic…

Complex Variables · Mathematics 2017-04-10 T. Hatziafratis , K. Kioulafa , V. Nestoridis

It is investigated the existence of a separately continuous function $f:X\times Y\to \mathbb R$ with an onepoint set of discontinuity for topological spaces $X$ and $Y$ which satisfy compactness type conditions. In particular, it is shown…

General Topology · Mathematics 2016-01-13 V. V Mykhaylyuk

Let $\Omega$ be a perfectly normal topological space, let $A$ be a non-empty $G_\delta$-subset of $\Omega$ and let $B_1(A)$ denote the space of all functions $A\to\mathbb{R}$ of Baire-one class on $A$. Let also $\|\cdot\|_\infty$ be the…

Classical Analysis and ODEs · Mathematics 2023-07-13 Waldemar Sieg

We characterize the Banach spaces X such that Ext(X, C(K))=0 for every compact space.

Functional Analysis · Mathematics 2007-05-23 Jesus M. F. Castillo , Yolanda Moreno

For a function space $X(\OO)$ satisfying weak assumptions we prove that the generic function in $X(\OO)$ is totally unbounded, hence non-extendable. We provide several examples of such spaces; they are mainly localized versions of classical…

Complex Variables · Mathematics 2018-11-13 V. Nestoridis , A. G. Siskakis , A. Stavrianidi , S. Vlachos

During the last few decades E. S. Thomas, S. J. Agronsky, J. G. Ceder, and T. L. Pearson gave an equivalent definition of the real Baire class 1 functions by characterizing their graph. In this paper, using their results, we consider the…

Classical Analysis and ODEs · Mathematics 2017-06-13 Balázs Maga

Let $S$ be a compact Hausdorff space and $X$ a complex manifold. We consider the space $C(S,X)$ of continuous maps $S\to X$, and prove that any bounded holomorphic function on this space can be continued to a holomorphic function, possibly…

Complex Variables · Mathematics 2023-03-22 László Lempert

Say that a cardinal number $\kappa$ is \emph{small} relative to the space $X$ if $\kappa <\Delta(X)$, where $\Delta(X)$ is the least cardinality of a non-empty open set in $X$. We prove that no Baire metric space can be covered by a small…

General Topology · Mathematics 2010-07-02 Santi Spadaro

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…

General Topology · Mathematics 2022-06-06 Alexander V. Osipov