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 1463

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

5 votes
Accepted

Covering spaces of surfaces

Given any covering map $\Sigma_h\to\Sigma_g$ between two surfaces, is there some kind of a ``standard" covering $M\to \Sigma_g$, which factors through $\Sigma_h$? …
HJRW's user avatar
  • 25.2k
6 votes
Accepted

Find a simple closed curve in $S$ which represents a commutator in $\pi_1 S$

The free subgroup generated by $a_1,b_1$ is carried by a one-holed torus $T$ embedded in the surface. Let $\gamma$ be a simple closed curve embedded in $T$, and consider $T\smallsetminus \gamma$. A …
HJRW's user avatar
  • 25.2k
7 votes

Generate $\mathrm{Mod}(S_g)$ by two Dehn twists

This is addressed in §3.5.2 of Farb and Margalit's Primer on Mapping Class Groups. The subgroups of mapping class groups generated by two Dehn twists $T_a,T_b$ are one of: $\mathbb{Z}$ if the curves …
HJRW's user avatar
  • 25.2k
2 votes

Identifying a curve on a closed surface of genus 4

As mentioned in comments, your picture is not entirely accurate. But perhaps this is what you're looking for? (Note that, if you had chosen a different gluing pattern for your once-punctured genus-tw …
HJRW's user avatar
  • 25.2k