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Related papers: Compactifiable classes of compacta

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In first order logic, it is known that you can define a topology so that the countable models of some theory $T$ form a Polish Space (i.e. completely metrizable second countable space). In this paper we use the Baldwin- Boney Relational…

Logic · Mathematics 2025-03-31 Georgios Marangelis

We review results concerning homogeneous compacta and discuss some open questions. It is established that indecomposable continua are Alexandroff (resp., Mazurkiewicz, or strong Cantor) manifolds with respect to the class of all continua.…

General Topology · Mathematics 2012-04-16 V. Todorov , V. Valov

We characterize the notion of definable compactness for topological spaces definable in o-minimal structures, answering questions of Peterzil and Steinhorn (1999) and Johnson (2018). Specifically, we prove the equivalence of various…

Logic · Mathematics 2025-04-29 Pablo Andújar Guerrero

First of all, we establish compactness of continuous mappings of the Orlicz--Sobolev classes $W^{1,\varphi}_{\rm loc}$ with the Calderon type condition on $\varphi$ and, in particular, of the Sobolev classes $W^{1,p}_{\rm loc}$ for $p>n-1$…

Complex Variables · Mathematics 2012-09-18 Vladimir Ryazanov , Ruslan Salimov , Evgeny Sevostyanov

We prove that each metrizable space (of cardinality less or equal to continuum) has a (first countable) uniform Eberlein compactification and each scattered metrizable space has a scattered hereditarily paracompact compactification. Each…

General Topology · Mathematics 2012-12-19 Taras Banakh , Arkady Leiderman

We present a construction, called the limit of a tree system of spaces (or, less formally, a tree of spaces). The construction is designed to produce compact metric spaces that resemble fractals, out of more regular spaces, such as closed…

Geometric Topology · Mathematics 2020-09-30 Jacek Swiatkowski

These lecture notes explain the construction and basic properties of the wonderful compactification of a complex semisimple group of adjoint type. An appendix discusses the more general case of a semisimple symmetric space.

Algebraic Geometry · Mathematics 2008-01-04 Sam Evens , Benjamin F Jones

A compact space $X$ is said to be minimal if there exists a map $f:X\to X$ such that the forward orbit of any point is dense in $X$. We consider rigid minimal spaces, motivated by recent results of Downarowicz, Snoha, and Tywoniuk [J. Dyn.…

Dynamical Systems · Mathematics 2020-02-13 J. P. Boroński , Jernej Činč , Magdalena Foryś-Krawiec

This note is devoted to proving the following result: given a compact metrizable group G, there is a compact metric space K such that G is isomorphic (as a topological group) to the isometry group of K.

Group Theory · Mathematics 2007-05-23 Julien Melleray

We discuss conditions under which certain compactifications of topological spaces can be obtained by composing the ultrafilter space monad with suitable reflectors. In particular, we show that these compactifications inherit their…

General Topology · Mathematics 2024-07-17 Ando Razafindrakoto

For each countable ordinal $\alpha$, we introduce an ideal $conv_\alpha$ and use it to characterize the class of all compact countable spaces which are homeomorphic to the space $\omega^{\alpha}\cdot n+1$ with the order topology. The…

General Topology · Mathematics 2025-03-18 Rafał Filipów , Małgorzata Kowalczuk , Adam Kwela

We show that it is consistent that for some uncountable cardinal k, all compactifications of the countable discrete space with remainders homeomorphic to $D^k$ are homeomorphic to each other. On the other hand, there are $2^c$ pairwise…

General Topology · Mathematics 2007-05-23 Mikhail Matveev

Given a compact space in a fixed universe of set theory, one can naturally define its interpretation in any ZFC extension of the universe. We investigate the stability of some classes of compact spaces with respect to extensions of this…

General Topology · Mathematics 2014-02-10 Wiesław Kubiś

We introduce and study the framework of compact metric structures and their associated notions of isomorphisms such as homeomorphic and bi-Lipschitz isomorphism. This is subsequently applied to model various classification problems in…

Logic · Mathematics 2016-10-04 Christian Rosendal , Joseph Zielinski

The notions of compactness and Hausdorff separation for generalized enriched categories allow us, as classically done for the category $\mathsf{Top}$ of topological spaces and continuous functions, to study $\textit{compactly generated…

Category Theory · Mathematics 2019-08-13 Willian Ribeiro

In this paper we introduce and study so-called $k^*$-metrizable spaces forming a new class of generalized metric spaces, and display various applications of such spaces in topological algebra, functional analysis, and measure theory. By…

General Topology · Mathematics 2011-10-11 T. O. Banakh , V. I. Bogachev , A. V. Kolesnikov

We define a class of spaces on which one may generalise the notion of compactness following motivating examples from higher-dimensional number theory. We establish analogues of several well-known topological results (such as Tychonoff's…

General Topology · Mathematics 2019-02-11 Raven Waller

It is proved that any countable index, universally measurable subgroup of a Polish group is open. By consequence, any universally measurable homomorphism from a Polish group into the infinite symmetric group $S_\infty$ is continuous. It is…

Logic · Mathematics 2011-04-19 Christian Rosendal

We shall prove a convergence result relative to sequences of Minkowski symmetrals of general compact sets. In particular, we investigate the case when this process is induced by sequences of subspaces whose elements belong to a finite…

Metric Geometry · Mathematics 2021-12-07 Jacopo Ulivelli

We construct a category that classifies compact Hausdorff spaces by their shape and finite topological spaces by their weak homotopy type.

Category Theory · Mathematics 2021-10-07 Pedro J. Chocano , Manuel A. Morón , Francisco R. Ruiz del Portal