Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 497904

A surface is a two-dimensional topological manifold. The term can also be used to describe a smooth surface, depending on the context.

4 votes

Maximal contractible-ish Hausdorff surfaces

$\omega$-bounded surfaces are well studied (see for instance Bagpipe theorem and the reference), and an $\omega$-bounded surface $X$ can be written as an increasing union of separable open subsets $\bigcup … There are many non-homeomorphic $\omega$-bounded surfaces $X$ that can be written as $\bigcup_{\alpha<\omega_1}X_\alpha$ where each $X_\alpha\simeq\mathbb{R}^2$; they are essentially the "long pipes" in …
new account's user avatar