English
Related papers

Related papers: Universal covering spaces, a footnote

200 papers

In this paper, it is shown that a topological space $X$ is compact iff every maximal ideal of the power set ring $\mathcal{P}(X)$ converges to exactly one point of $X$. Then as an application, simple and ring-theoretic proofs are provided…

Commutative Algebra · Mathematics 2020-11-05 Abolfazl Tarizadeh

We study compact K\"ahler threefolds X with infinite fundamental group whose universal cover can be compactified. Combining techniques from $L^2$ -theory, Campana's geometric orbifolds and the minimal model program we show that this…

Algebraic Geometry · Mathematics 2010-09-21 Benoît Claudon , Andreas Hoering

We develop the notion of a geometric covering of a rigid space X, which yields a much larger class of covering spaces than that studied previously by de Jong. Geometric coverings of X are closed under disjoint unions and are \'etale local…

Algebraic Geometry · Mathematics 2022-03-24 Piotr Achinger , Marcin Lara , Alex Youcis

We show that if there exists a topologically expansive homeomorphism on a uniform space, then the space is always a regular space. Through examples we show that in general composition of topologically expansive homeomorphisms need not be…

Dynamical Systems · Mathematics 2019-03-26 Ali Barzanouni , Ekta Shah

For $m=2$ and $m=3$ we prove that any connected, oriented, open manifold $M^m$ admits a simple branched covering map over $\mathbb{R}^m$. When $M$ has $k$ ends and $k$ is finite, the degree of the cover can be taken to be $mk$. Regardless…

Geometric Topology · Mathematics 2025-12-10 Mark Hughes , Alexandra Kjuchukova , Maggie Miller

Given a definably compact group G in a saturated o-minimal structure, there is a canonical homomorphism from G to a compact real Lie group F(G). We establish a similar result for the (o-mininimal) universal cover of a definably compact…

Logic · Mathematics 2009-11-30 A. Berarducci , M. Mamino

Let X be a compact K\"ahler manifold such that the universal cover admits a compactification. We conjecture that the fundamental group is almost abelian and reduce it to a classical conjecture of Iitaka.

Algebraic Geometry · Mathematics 2014-10-13 Benoît Claudon , Andreas Hoering

A generalized topology in a set $X$ is a collection $\text{Cov}_X$ of families of subsets of $X$ such that the triple $(X,\bigcup \text{Cov}_X,\text{Cov}_X)$ is a generalized topological space in the sense of Delfs and Knebusch. In this…

General Topology · Mathematics 2020-09-09 Artur Piȩkosz , Eliza Wajch

Covering spaces are a fundamental tool in algebraic topology because of the close relationship they bear with the fundamental groups of spaces. Indeed, they are in correspondence with the subgroups of the fundamental group: this is known as…

Logic in Computer Science · Computer Science 2026-05-01 Samuel Mimram , Émile Oleon

Limit and Pseudotopological spaces are two generalizations of topological spaces which are defined by indicating what filters converge under some axioms. In this article, we introduce covering spaces and set forth some necessary conditions…

General Topology · Mathematics 2024-03-29 Jonathan Treviño-Marroquín

Let $H$ be a connected semisimple linear algebraic group defined over $\mathbb C$ and $X$ a compact connected Riemann surface of genus at least three. Let ${\mathcal M}'_X(H)$ be the moduli space parametrising all topologically trivial…

Algebraic Geometry · Mathematics 2007-05-23 V. Balaji , I. Biswas , D. S. Nagaraj , P. E. Newstead

These lecture notes from a first course in algebraic topology use the fundamental group and orbit categories to classify covering spaces.

Algebraic Topology · Mathematics 2011-06-29 Jesper M. Møller

The path component space of a topological space $X$ is the quotient space $\pi_0(X)$ whose points are the path components of $X$. We show that every Tychonoff space $X$ is the path-component space of a Tychonoff space $Y$ of weight…

General Topology · Mathematics 2020-04-14 Taras Banakh , Jeremy Brazas

Let F be a finitely generated discrete group. Given a covering map H to G of Lie groups with G either compact or complex reductive, there is an induced covering map Hom(F, H) to Hom(F, G). We show that when the fundamental group of G is…

Algebraic Topology · Mathematics 2018-05-09 Sean Lawton , Daniel Ramras

For any compact Lie group $G$ and any $n$ we construct a smooth $G$-manifold $U_n(G)$ such that any smooth $n$-dimensional $G$-manifold can be embedded in $U_n(G)$ with a trivial normal bundle. Furthermore, we show that such embeddings are…

Algebraic Topology · Mathematics 2025-01-03 Arthur G. Wasserman

In classical covering space theory, a covering map induces an injection of fundamental groups. This paper reveals a dual property for certain quotient maps having connected fibers, with applications to orbit spaces of vector fields and leaf…

General Topology · Mathematics 2013-03-06 Jack S. Calcut , Robert E. Gompf , John D. McCarthy

We prove that an equivalent condition for a uniform space to be coverable is that the images of the natural projections in the fundamental inverse system are uniformly open in a certain sense. As corollaries we (1) obtain a concrete way to…

General Topology · Mathematics 2007-10-11 Conrad Plaut

Let $X$ be a topological space. We consider certain generalized configuration spaces of points on $X$, obtained from the cartesian product $X^n$ by removing some intersections of diagonals. We give a systematic framework for studying the…

Algebraic Topology · Mathematics 2020-02-19 Dan Petersen

Let X be an algebraic variety covered by open charts isomorphic to the affine space and q: X' \to X be the universal torsor over X. We prove that the automorphism group of the quasiaffine variety X' acts on X' infinitely transitively. Also…

Algebraic Geometry · Mathematics 2014-10-07 Ivan Arzhantsev , Alexander Perepechko , Hendrik Süß

This paper identifies the homotopy theories of topological stacks and orbispaces with unstable global homotopy theory. At the same time, we provide a new perspective by interpreting it as the homotopy theory of `spaces with an action of the…

Algebraic Topology · Mathematics 2020-01-13 Stefan Schwede