Non-metrizable manifolds and contractibility

We investigate whether non-metrizable manifolds in various classes can be homotopy equivalent to a CW-complex (in short: heCWc), and in particular contractible. We show that a non-metrizable manifold cannot be heCWc if it has one of the following properties: it contains a countably compact non-compa...

Full description

Saved in:
Bibliographic Details
Main Author: Mathieu Baillif
Format: Article
Language:English
Published: Universitat Politècnica de València 2025-04-01
Series:Applied General Topology
Subjects:
Online Access:https://polipapers.upv.es/index.php/AGT/article/view/21796
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigate whether non-metrizable manifolds in various classes can be homotopy equivalent to a CW-complex (in short: heCWc), and in particular contractible. We show that a non-metrizable manifold cannot be heCWc if it has one of the following properties: it contains a countably compact non-compact subspace; it contains a copy of an ω1-compact subspace of an ω1-tree; it contains a non-Lindelöf closed subspace functionally narrow in it. (These results hold for more general spaces than just manifolds.) We also show that the positive part of the tangent bundle of the longray is never heCWc for any smoothing. These theorems follow from stabilization properties of real valued maps. On a more geometric side, we also show that the Prüfer surface, which has been shown to be contractible long ago, has an open submanifold with trivial homotopy groups which is not heCWc. On the other end of the spectrum, we show that there is a non-metrizable contractible Type I surface.
ISSN:1576-9402
1989-4147