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Related papers: Hurewicz theorem for extension dimension

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We describe the second homotopy group of any CW-complex $K$ by analyzing the universal cover of a locally finite model of $K$ using the notion of $G$-coloring of a partially ordered set. As applications we prove a generalization of the…

Algebraic Topology · Mathematics 2014-12-18 Jonathan Ariel Barmak , Elias Gabriel Minian

We give an elementary proof of the Hurewicz theorem relating homotopy and homology groups of a cubical Kan complex. Our approach is based on the notion of a loop space of a cubical set, developed in a companion paper ``Homotopy groups of…

Algebraic Topology · Mathematics 2024-09-09 Daniel Carranza , Chris Kapulkin , Andrew Tonks

We present some results related to theorems of Pasynkov and Torunczyk on the geometry of maps of finite dimensional compacta.

General Topology · Mathematics 2007-05-23 Michael Levin , Wayne Lewis

Generalizing de Vries Compactification Theorem and strengthening Leader Local Compactification Theorem, we describe the partially ordered set $(\LL(X),\le)$ of all (up to equivalence) locally compact Hausdorff extensions of a Tychonoff…

General Topology · Mathematics 2009-10-20 Georgi Dimov

Let $M$ be a complete metric $ANR$-space such that for any metric compactum $K$ the function space $C(K,M)$ contains a dense set of Bing (resp., Krasinkiewicz) maps. It is shown that $M$ has the following property: If $f\colon X\to Y$ is a…

General Topology · Mathematics 2009-01-04 Vesko Valov

In this paper, we introduced $\alpha$-Hurewicz $\&$ $\theta$-Hurewicz properties in a topological space $X$ and investigated their relationship with other selective covering properties. We have shown that for an extremally disconnected…

General Topology · Mathematics 2023-07-04 Gaurav Kumar , Sumit Mittal , Brij K. Tyagi

In this paper we prove the equivalence of the questions of B.A. Pasynkov and V.V. Uspenskij. We also get some partial results answering these questions in affirmative. As a corollary to these results we get an extention of the Hurewicz…

General Topology · Mathematics 2007-05-23 Yuri A. Turygin

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 prove that any continuous mapping $f:E\to Y$ on a completely metrizable subspace $E$ of a perfect paracompact space $X$ can be extended to a Lebesgue class one mapping $g:X\to Y$ (i.e. for every open set $V$ in $Y$ the preimage…

General Topology · Mathematics 2014-07-03 Olena Karlova

A space $X$ is projectively Hurewicz provided every separable metrizable continuous image of $X$ is Hurewicz. In this paper we prove that the projectively Hurewicz property is $t$-invariant, i.e., if $C_p(X)$ is homeomorphic to $C_p(Y)$ and…

General Topology · Mathematics 2023-06-06 Alexander V. Osipov

In this note, we characterize when the Vietoris space of compact subsets of a given space has the Hurewicz property in terms of a selection principle on the given space itself using $k$-covers and the notion of groupability introduced by…

General Topology · Mathematics 2023-08-22 Christopher Caruvana

Let f be a proper holomorphic mapping between bounded domains D and D' in C^2. Let M, M' be open pieces on the boundaries of D and D' respectively, that are smooth, real analytic and of finite type. Suppose that the cluster set of M under f…

Complex Variables · Mathematics 2007-05-23 Rasul Shafikov , Kaushal Verma

We fill a lacuna in the literature by giving a version in dimension 1 of the Relative Hurewicz Theorem, and relate this to abelianisations of groupoids, covering spaces and covering morphisms of groupoids, and Crowell's notion of derived…

Algebraic Topology · Mathematics 2017-03-21 Ronald Brown

The Hurewicz theorem is a fundamental result in classical dimension theory concerning continuous maps which lower topological dimension. We study whether or not its analogue holds for mean dimension of dynamical systems. Our first main…

Dynamical Systems · Mathematics 2022-06-08 Masaki Tsukamoto

We extend the definition of quasi-finite complexes by considering not necessarily countable complexes. We provide a characterization of quasi-finite complexes in terms of L-invertible maps and dimensional properties of compactifications.…

General Topology · Mathematics 2007-05-23 Alex Karasev , Vesko Valov

The main aim of this work is to show, in the absence of the Axiom of Choice, fundamental results on $\mathbf{E}$-compact extensions of $\mathbf{E}$-completely regular spaces, in particular, on Hewitt realcompactifications and Banaschewski…

General Topology · Mathematics 2023-10-16 AliReza Olfati , Eliza Wajch

We prove in this note a result on extension of meromorphic mappings, which can be considered as a direct generalisation of the Hartogs extension theorem for holomorphic functions. Namely: THEOREM. Every meromorphic mapping $f:H_n^q(r)\to…

Complex Variables · Mathematics 2016-09-07 Sergei Ivashkovich , Alessandro Silva

A homological selection theorem for C-spaces, as well as, a finite-dimensional homological selection theorem is established. We apply the finite-dimensional homological selection theorem to obtain fixed-point theorems for usco homologically…

General Topology · Mathematics 2017-02-14 Vesko Valov

In this paper we present a proof of Hartogs' extension theorem, following T. Sobieszek's paper from 2003. Hartogs' theorem provides a large class of domains where holomorphic functions have analytic continuation to larger domains, and is "a…

Complex Variables · Mathematics 2016-08-03 Aleksander Simonič

We demonstrate that the classical Michael selection theorem for l.s.c. mappings with a collectionwise normal domain can be reduced only to compact-valued mappings modulo Dowker's extension theorem for such spaces. The idea used to achieve…

General Topology · Mathematics 2018-05-22 Valentin Gutev , Narcisse Roland Loufouma Makala