Skip to main content

All Questions

6 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5 votes
0 answers
228 views

Automorphism groups of cocompact Fuchsian groups as mapping class groups

Let $\Gamma$ be a cocompact Fuchsian group. So it has presentation $$\langle x_1,y_1, \dots, x_g,y_g,z_1, \ldots, z_r \mid [x_1,y_1] \cdots [x_g,y_g]z_1 \cdots z_r=1, \ z_i^{m_i}=1 \rangle$$ for some $...
AGenevois's user avatar
  • 8,401
4 votes
0 answers
209 views

Image of the mapping class group of surfaces into automorphism group?

Let $S_{g,p}^n$ be a compact oriented surface of genus $g$ with $p$ punctures and $n$ boundary components, and $\operatorname{Mod}(S)$ and $\operatorname{PMod}(S)$ be the mapping class group and the ...
qkqh's user avatar
  • 347
3 votes
0 answers
228 views

What is known about the map $\text{Mod}_g^1 \rightarrow \text{Aut}(F_{2g})$?

Follow up question, edited in on 12/20 below: Letting $\text{Mod}_g^1$ be the mapping class group of a surface with one boundary component (and basepoint on the boundary) and identify its fundamental ...
Chase's user avatar
  • 181
3 votes
0 answers
141 views

Translation discreteness of pseudo-Anosov elements

Consider the action of mapping class groups on the curve graphs. A pseudo-Anosov element $g$ acts by a loxodromic isometry on the hyperbolic curve graphs. The translation length of $g$ is the limit $\...
stephen's user avatar
  • 619
3 votes
0 answers
414 views

Geometric intersection number for product of elements of the fundamental group

Let $F$ be a hyperbolic surface and $p\in F$ be a point. Consider $\pi_1(F,p)$, the fundamental group of $F$ with base point $p$. Let $x,y\in \pi_1(F,p)$ and $z$ be a simple closed curve in $F$ such ...
Cusp's user avatar
  • 1,713
2 votes
0 answers
139 views

Image of the pure braid group under the Artin presentation into the automorphism group of the nilpotent quotient of a free group?

As I know, it is unknown that the image of the mapping class group of the surface and its Johnson filtration under the higher Johnson homomorphisms. There are a relationship between the mapping class ...
qkqh's user avatar
  • 347