English
Related papers

Related papers: Partitions and point-finite covers of Baire spaces

200 papers

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 define and study an effective version of the Wadge hierarchy in computable quasi-Polish spaces which include most spaces of interest for computable analysis. Along with hierarchies of sets we study hierarchies of k-partitions which are…

Logic in Computer Science · Computer Science 2021-02-16 Victor Selivanov

According to a result of Kocinac and Scheepers, the Hurewicz covering property is equivalent to a somewhat simpler selection property: For each sequence of large open covers of the space one can choose finitely many elements from each cover…

General Topology · Mathematics 2010-11-02 Boaz Tsaban

We introduce the open degree of a compact space, and we show that for every natural number n, the separable Rosenthal compact spaces of degree n have a finite basis.

General Topology · Mathematics 2015-12-29 Antonio Avilés , Stevo Todorcevic

For every couple of Hausdorff functions $ \psi$ and $\varphi $ verifying some mild assumptions, there exists a compact subset $ K $ of the Baire space such that the $ \varphi$-Hausdorff measure and the $ \psi$-packing measure on $ K$ are…

Functional Analysis · Mathematics 2025-11-10 Mathieu Helfter

We give an alternative proof of the Hurwitz existence problem for branched covers of $\mathbb{P}^1$ in the case where the number of ramification points equals the number of branch points, that is, where all the ramification profiles are of…

Algebraic Geometry · Mathematics 2026-05-06 Ciro Ciliberto , Andreas Leopold Knutsen , Sara Torelli

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

It is proved that no non-meager subspace of the space $[\omega]^\omega$ equipped with the Ellentuck topology does admit a Kuratowski partition, that is such a subset cannot be covered by a family $\mathfrak{F}$ of disjoint relatively meager…

Logic · Mathematics 2014-03-28 Ryszard Frankiewicz , Sławomir Szczepaniak

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

We prove that, for every n, the topological space {\omega}_n^{\omega} (where {\omega}_n has the discrete topology) can be partitioned into {\omega}_n copies of the Baire space. Using this fact, the authors then prove two new theorems about…

General Topology · Mathematics 2014-06-06 William R. Brian , Arnold W. Miller

All spaces are assumed to be separable and metrizable. Consider the following properties of a space $X$. (1) $X$ is Polish. (2) For every countable crowded $Q\subseteq X$ there exists a crowded $Q'\subseteq Q$ with compact closure. (3)…

General Topology · Mathematics 2014-06-02 Andrea Medini , Lyubomyr Zdomskyy

We provide a classification of complex projective surfaces with a holomorphic foliation whose group of birational symetries is infinite.

Complex Variables · Mathematics 2007-05-23 S. Cantat , C. Favre

The Wadge hierarchy was originally defined and studied only in the Baire space (and some other zero-dimensional spaces). We extend it here to arbitrary topological spaces by providing a set-theoretic definition of all its levels. We show…

Logic · Mathematics 2019-11-11 Victor Selivanov

We have defined almost separable space. We show that like separability, almost separability is $c$ productive and converse also true under some restrictions. We establish a Baire Category theorem like result in Hausdorff, Pseudocompacts…

General Topology · Mathematics 2020-02-13 Sagarmoy Bag , Ram Chandra Manna , Sourav Kanti Patra

We study Hurewicz fibrations between finite T$_0$--spaces from a combinatorial viewpoint and give strong conditions that a continuous map between finite T$_0$--spaces must satisfy in order to be a Hurewicz fibration. We also show that there…

Algebraic Topology · Mathematics 2019-07-10 Nicolás Cianci , Miguel Ottina

A classical branched cover is an open surjection of compact Hausdorff spaces with uniformly bounded finite fibers and analogously, a quantum branched cover is a unital $C^*$ embedding admitting a finite-index expectation. We show that…

Functional Analysis · Mathematics 2024-09-27 Alexandru Chirvasitu

We prove a q-analogue of the Carter-Payne theorem in the case where the differences between the parts of the partitions are sufficiently large. We identify a layer of the Jantzen filtration which contains the image of these Carter-Payne…

Representation Theory · Mathematics 2009-12-11 Sinead Lyle , Andrew Mathas

Building on and extending tools from variational analysis, we prove Kuratowski convergence of sets of simplicial area minimizers to minimizers of the smooth Douglas-Plateau problem under simplicial refinement. This convergence is with…

Numerical Analysis · Mathematics 2017-02-20 Henrik Schumacher , Max Wardetzky

The Baire category theorem states that every complete pseudometric space is a Baire space. There are some results in metric spaces which have their analogue in uniform spaces, however this is not one of them. Nonetheless, since the Baire…

If $f : X\mapsto Y$ is a function having Baire property from a metric space $X$ into a separable metric space $Y$ , then $f$ is continuous except on a set of first category. Kuratowski asked whether the condition of separability could be…

Functional Analysis · Mathematics 2024-08-19 Sanjib Basu , Abhit Chandra Pramanik
‹ Prev 1 2 3 10 Next ›