3
votes
2answers
138 views
Random metrics on compact orientable surfaces
Hello everyone,
Let $S_g$ be a compact orientable surface of genus $g \geq 2$, and let $\mathcal{A}$ be the set of $\mathcal{C}^{\infty}$ Riemanniann metric on $S_g$ endowed with …
5
votes
1answer
150 views
Fixing a proof of the systolic inequality for higher genus surfaces
I'm currently learning some stuffs about systolic inequalities. While reading the relevant sections (p329 to 340) in Berger's Panoramic View of Riemannian Geometry, I noticed a gap …
0
votes
0answers
69 views
Which surfaces can be completely defined by a single parameterization?
It can be easily shown that any closed and bounded surface of $\mathbb{R}^3$ cannot be covered by a single surface patch, i.e. cannot be homeomorphic to an open set of $\mathbb{R}^ …
3
votes
2answers
291 views
Surface Laplace-Beltrami without coordinates, exterior calculus?
Let $f: M \rightarrow \mathbb{R}^3$ be an immersion of a surface $M$. For pedagogical purposes (i.e., I'm teaching a class!) I am looking for an expression for the scalar Laplace- …
3
votes
3answers
684 views
Covering spaces of surfaces
Let $\Sigma_g$ be a surface of genus $g\ge 2$, and let $\Sigma_k$ be an $m$-sheeted covering
space of $\Sigma_g$. It is known that $k=m(g-1)+1$.
An example of such a covering sp …
1
vote
1answer
258 views
Description of regular covering maps between surfaces.
This is an improved and hopefully a more precise version of the question http://mathoverflow.net/questions/104718/covering-spaces-of-surfaces.
Question: Given a regular covering m …
6
votes
2answers
319 views
Do the following set of Dehn twists generate the mapping class group?
If $S$ is the surface illustrated below, do the Dehn twists about the red curves generate the mapping class group $\operatorname{MCG}(S,\partial S)$?
5
votes
2answers
208 views
What is the homotopy type of the space of simple closed curves isotopic to a given one?
For surfaces there are many statements along the lines of: if two simple closed curves are homotopic, they are isotopic. I'm interested in such questions for families of curves.
M …
14
votes
4answers
886 views
Morse theory in TOP and PL categories?
Apparently there are topological and piecewise linear versions of Morse theory. I would like to know of references that treat these topics.
How is a Morse function defined for com …
5
votes
2answers
549 views
Pursuit-Evasion on a Manifold
I know pursuit-evasion has been studied in many contexts, including
on a manifold (e.g., Melikyan,
"Geometry of Pursuit-Evasion Games on Two-Dimensional Manifolds"),
but I have not …
3
votes
3answers
260 views
Lagrangian Kleinian bottles
I remember some talks some time ago about proofs of nonexistence of Lagrangian Kleinian bottles in C^2 for the standard symplectic structure, mentioning that this were the only com …
7
votes
1answer
607 views
Classification of surfaces and the TOP, DIFF and PL categories for manifolds
A surface is simply a 2-manifold. The classification theorem for compact connected surfaces (with boundary) is commonly regarded in the categories TOP, DIFF and PL. Well known proo …
2
votes
1answer
367 views
Parallel translation on surfaces
Parallel translation of a vector along a geodesic in a surface is characterized by the following three properties:
The vector being transported moves continuously.
It has constan …
1
vote
0answers
163 views
surfaces dominated by a product of curves
I would like to know for which projective smooth surfaces over a finite field there exists a dominant rational map from a product of curves to the surface
4
votes
1answer
234 views
Representing groups with two generators as graph automorphisms
Suppose we have a group $G$ which can be generated by two elements $x$, $y$. Call $H$, $K$, $L$ the subgroups of $G$ generated by $x$, $y$ and $y^{-1}x^{-1}$, respectively.
With t …

