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We construct homeomorphisms of compacta from relations between finite graphs representing their open covers. Applied to the pseudoarc, this yields simple Fra\"iss\'e theoretic proofs of several important results, both old and new.…

General Topology · Mathematics 2024-12-31 Tristan Bice , Maciej Malicki

We consider the covering map $\pi:\mathbb{C}^n\to \mathbb{T}$ of a compact complex torus. Given an algebraic variety $X\subseteq \mathbb{C}^n$ we describe the topological closure of $\pi(X)$ in $\mathbb T$. We obtain a similar description…

Algebraic Geometry · Mathematics 2017-04-17 Ya'acov Peterzil , Sergei Starchenko

This paper constructs a continuous decomposition of the Sierpi\'nski curve into acyclic continua one of which is an arc. This decomposition is then used to construct another continuous decomposition of the Sierpi\'nski curve. The resulting…

Geometric Topology · Mathematics 2007-05-23 Carl R. Seaquist

We show that a toral homeomorphism which is homotopic to the identity and topologically semiconjugate to an irrational rotation of the circle is always a pseudo-rotation (i.e. its rotation set is a single point). In combination with recent…

Dynamical Systems · Mathematics 2016-11-18 Andres Koropecki , Alejandro Passeggi , Martín Sambarino

Some new classes of compacta $K$ are considered for which $C(K)$ endowed with the pointwise topology has a countable cover by sets of small local norm--diameter.

Functional Analysis · Mathematics 2015-10-20 Wiesław Kubiś , Aníbal Moltó , Stanimir Troyanski

Various theorems on convergence of general space homeomorphisms are proved and, on this basis, theorems on convergence and compactness for classes of the so-called ring $Q$--homeomorphisms are obtained. In particular, it was established by…

Complex Variables · Mathematics 2012-08-21 Vladimir Ryazanov , Evgeny Sevost'yanov

Let $G$ be a compact Lie group. (Compact) topological $G$-manifolds have the $G$-homotopy type of (finite-dimensional) countable $G$-CW complexes (2.5). This partly generalizes Elfving's theorem for locally linear $G$-manifolds [Elf96],…

Geometric Topology · Mathematics 2018-06-26 Qayum Khan

Let $G$ be a matrix group. Topological $G$-manifolds with Palais-proper action have the $G$-homotopy type of countable $G$-CW complexes (3.2). This generalizes E Elfving's dissertation theorem for locally linear $G$-manifolds (1996). Also…

Geometric Topology · Mathematics 2021-01-05 Qayum Khan

The paper deals with the program of determining the complexity of various homeomorphism relations. The homeomorphism relation on compact Polish spaces is known to be reducible to an orbit equivalence relation of a continuous Polish group…

Geometric Topology · Mathematics 2021-12-07 Vadim Kulikov

The Lefschetz fixed point theorem provides a powerful obstruction to the existence of minimal homeomorphisms on well-behaved spaces such as finite CW-complexes. We show that these obstructions do not hold for more general spaces. More…

Dynamical Systems · Mathematics 2022-02-02 Robin J. Deeley , Ian F. Putnam , Karen R. Strung

Hrushovski proved the Lie model theorem in full generality with model theoretic methods. The theorem states that for every approximate group there exists a generalized definable locally compact model, which, simplifying, is a…

Logic · Mathematics 2025-12-17 Beatrice Degasperi

We introduce and investigate a topological version of St\"ackel's 1907 characterization of finite sets, with the goal of obtaining an interesting notion that characterizes usual compactness (or a close variant of it). Define a $T_2$…

General Topology · Mathematics 2024-03-11 Abhijit Dasgupta

We prove a generalization of the Shapiro-Shapiro conjecture on Wronskians of polynomials, allowing the Wronskian to have complex conjugate roots. We decompose the real Schubert cell according to the number of real roots of the Wronski map,…

Algebraic Geometry · Mathematics 2021-07-12 Jake Levinson , Kevin Purbhoo

For a compact space $K$ we denote by $C_w(K)$ ($C_p(K)$) the space of continuous real-valued functions on $K$ endowed with the weak (pointwise) topology. In this paper we address the following basic question which seems to be open: Suppose…

Functional Analysis · Mathematics 2015-06-17 Mikołaj Krupski

In a recent paper \cite{T} the fact that a class of locally compact metric spaces $X$, among which are Euclidean spaces, are not homemorphic to their punctured version $X\men\{p\}$, was given an interesting new proof which does not use…

General Topology · Mathematics 2023-08-08 Giuseppe De Marco

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

We prove that any topological loop homeomorphic to a sphere or to a real projective space and having a compact-free Lie group as the inner mapping group is homeomorphic to the circle. Moreover, we classify the differentiable $1$-dimensional…

Group Theory · Mathematics 2015-07-03 Ágota Figula , Karl Strambach

Let $Homeo(\Omega)$ be the group of all homeomorphisms of a Cantor set $\Omega$. We study topological properties of $Homeo(\Omega)$ and its subsets with respect to the uniform $(\tau)$ and weak $(\tau_w)$ topologies. The classes of…

Dynamical Systems · Mathematics 2007-05-23 Sergey Bezuglyi , Anthony H. Dooley , Jan Kwiatkowski

We prove that any minimal $2$-torus homeomorphism which is isotopic to the identity and whose rotation set is not just a point exhibits uniformly bounded rotational deviations on the perpendicular direction to the rotation set. As a…

Dynamical Systems · Mathematics 2020-02-11 Alejandro Kocsard

In this article we use techniques developed by Hrushovski-Loeser to study certain metric properties of the Berkovich analytification of a finite morphism of smooth connected projective curves. In recent work, M. Temkin proved a radiality…

Algebraic Geometry · Mathematics 2018-01-03 John Welliaveetil