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Related papers: Some anomalous examples of lifting spaces

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We prove a lifting theorem for odd Frattini covers of finite groups. Using this, we characterize solvable groups and more generally p-solvable groups in terms of containing a triple of elements of distinct prime power orders with product 1.…

Group Theory · Mathematics 2011-12-21 Robert Guralnick , Pham Huu Tiep

We study an analogue of fibrations of topological spaces with the homotopy lifting property in the setting of C*-algebra bundles. We then derive an analogue of the Leray-Serre spectral sequence to compute the K-theory of the fibration in…

K-Theory and Homology · Mathematics 2008-10-02 Siegfried Echterhoff , Ryszard Nest , Herve Oyono-Oyono

The paper is devoted to introduce some notions extending the unique path lifting property from a homotopy viewpoint and to study their roles in the category of fibrations. First, we define some homotopical kinds of the unique path lifting…

Algebraic Topology · Mathematics 2016-01-15 Mehdi Tajik , Behrooz Mashayekhy , Ali Pakdaman

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

We define several topological spaces whose points are quivers with a given infinite vertex set $X$. In the special case when $X$ is countably infinite, we show that two of the spaces of interest are homeomorphic to the Baire space…

Combinatorics · Mathematics 2026-04-21 Benjamin Grant

Let $M_j$ be a sequence of Riemannian manifolds with sectional curvature bound below collapsing to a compact Alexandrov space $X$ of dimension $k$. Suppose that all but finitely many points of $X$ are $(k,\delta)$-strained and that the…

Differential Geometry · Mathematics 2023-01-18 Tadashi Fujioka

We carefully present an elementary proof of the well known theorem that each homotopy group (or, in degree zero, pointed set) of the inverse limit of a tower of fibrations maps naturally onto the inverse limit of the homotopy groups (or, in…

Algebraic Topology · Mathematics 2015-07-08 Philip S. Hirschhorn

We present general techniques for constructing functorial factorizations appropriate for model structures that are not known to be cofibrantly generated. Our methods use "algebraic" characterizations of fibrations to produce factorizations…

Algebraic Topology · Mathematics 2013-04-24 Tobias Barthel , Emily Riehl

In this note, the idea of finite dimensional $L^p$ spaces is transferred to Lorentzian length spaces to provide an example that is locally nowhere Minkowskian. Looking at the sectional curvature bounds of this example leads to the more…

Differential Geometry · Mathematics 2025-08-01 Jona Röhrig

A result of the author shows that the behavior of Gowers norms on bounded exponent abelian groups is connected to finite nilspaces. Motivated by this, we investigate the structure of finite nilspaces. As an application we prove inverse…

Combinatorics · Mathematics 2010-11-05 Balazs Szegedy

We construct a one dimensional, second countable, simply connected manifold that exhibits a single non Hausdorff fiber, sufficient to destroy the fundamental properties of classical covering space theory. The space, called the line with k…

General Topology · Mathematics 2025-07-01 Abhiram Sripat

A topological space ${\mathcal X}$ is reversible iff each continuous bijection (condensation) $f: {\mathcal X} \rightarrow {\mathcal X}$ is a homeomorphism; weakly reversible iff whenever ${\mathcal Y}$ is a space and there are…

General Topology · Mathematics 2024-12-11 Miloš S. Kurilić

The canonical covering maps from Hurwitz varieties to configuration varieties are important in algebraic geometry. The scheme-theoretic fiber above a rational point is commonly connected, in which case it is the spectrum of a Hurwitz number…

Number Theory · Mathematics 2016-08-31 David P. Roberts

Let ${\rm Fin}(X)$ be the hyperspace consisting of non-empty finite subsets of a space $X$ endowed with the Vietoris topology. In this paper, we characterize a metrizable space $X$ whose hyperspace ${\rm Fin}(X)$ is homeomorphic to the…

General Topology · Mathematics 2015-12-08 Katsuhisa Koshino

Although Berkovich spaces may fail to be metrizable when defined over too big a field, we prove that a large part of their topology can be recovered through sequences: for instance, limit points of subsets are actual limits of sequences and…

Algebraic Geometry · Mathematics 2012-12-17 Jérôme Poineau

A classical theorem of Hurewicz characterizes spaces with the Hurewicz covering property as those having bounded continuous images in the Baire space. We give a similar characterization for spaces X which have the Hurewicz property…

General Topology · Mathematics 2014-09-02 Boaz Tsaban , Lyubomyr Zdomskyy

We answer an open question concerning the boundedness of canonical fiber spaces in high dimensions and prove the following: for any set of integers $n\geq 3$, $0<d<n$ and $N>0$, there exists a nonsingular projective $n$-fold $X$ of general…

Algebraic Geometry · Mathematics 2017-05-04 Meng Chen , Zhi Jiang

This note exhibits singular fibrations over the 2-sphere whose regular fibers are connected surfaces of arbitrarily high genus, but which admit no sections. These include achiral Lefschetz fibrations, as well as generic maps for which some…

Geometric Topology · Mathematics 2025-06-24 Robert E. Gompf

We find universal spaces for Alexandroff and finite spaces and explore some of its topological properties as well as their description as inverse limits of finite spaces and Alexandroff extensions. They can be used as a natural environment…

General Topology · Mathematics 2024-12-02 Diego Mondéjar

We develop a generalized covering space theory for a class of uniform spaces called coverable spaces. Coverable spaces include all geodesic metric spaces, connected and locally pathwise connected compact topological spaces, in particular…

Algebraic Topology · Mathematics 2007-05-23 Valera Berestovskii , Conrad Plaut