Questions tagged [teichmuller-theory]
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222
questions
3
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Fenchel–Nielsen coordinates vs Fock–Goncharov coordinates
Consider an orientable surface $S$ and its Teichmüller space $S$, which is the space of representations of its fundamental group $T(S)=\{\rho: \pi_1(S) \to \operatorname{SL}(2,\mathbb{R})\}$. Fock and ...
- 1,213
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0
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81
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What is mean of action of group on tower?
What is mean of action of group on tower ?in the page 17 of following paper (action on teichmuller tower )
In Hatcher, Allen; Lochak, Pierre; Schneps, Leila, On the Teichmüller tower of mapping class ...
- 107
1
vote
1
answer
59
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Measured geodesic laminations have either discrete or Cantor set local cross-sections
I'm reading through Kerckhoff's paper "The Nielsen Realization Problem": https://www.jstor.org/stable/2007076.
In section 1, after he defines measured geodesic laminations, he makes the ...
- 605
7
votes
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117
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The relation between Wolf's and Teichmüller's parametrization of the Teichmüller space
Let $\mathcal{T}_g$ be the Teichmüller space of Riemannian surface structures on an oriented 2-dimensional manifold of genus $g$. Fix a point $S \in \mathcal{T}_g$. There are two different ways to ...
- 758
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votes
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60
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Automorphism group of moduli space $M_{0,n}$
Statement: the group of complex automorphisms of the moduli space $M_{0,n}$ of complex $n$-marked genus 0 curves is isomorphic to $\mathfrak S_n$: one has ${\rm Aut}(M_{0,n})=\mathfrak S_n$
I believe ...
- 798
3
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0
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57
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Behavior of the period map at the boundary of the Teichmuller space
Fix a compact oriented surface $S$ of genus $g$. Any complex structure $J$ on $S$ gives by the Hodge decomposition a linear complex structure $J'$ on $H_1(S,\mathbb{R})$. The map $J\mapsto J'$ is a ...
- 959
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58
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Equicontinuity, Beltrami coefficients and Sequence of top/bottom semi-annuli
In the Beltrami equation literature, one approach to showing equicontinuity for pairs $(f_{n},\mu_{n})$ (where $\partial_{\bar{z}}f_{n}=\mu_{n}(z)\partial_{z}f_{n}$) is via the relations of moduli and ...
- 1,378
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0
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177
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What is the topology of the Hitchin component?
Let $S$ be a closed orientable connected surface of genus $g\geq2$.
In Lie groups and Teichmüller space Hitchin shows that one of the component of $\chi(S)=\operatorname{Hom}^{+}(\pi_1(S),\...
- 443
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votes
2
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232
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Fenchel-Nielsen length-length coordinates on Teichmueller space?
Let $S$ be closed hyperbolic surface with genus $g\geq 2$. Let $Teich(S)$ be the Teichmueller space of $S$. It's well known that $Teich(S)$ is diffeomorphic to a (6g-6)-dimensional cell, where a ...
- 2,186
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2
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608
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What do the components of $\operatorname{Hom}(\pi_1(S),\operatorname{SL}_n(\mathbb{R}))$ look like?
Let $S$ be a closed orientable surface of genus at least $2$. I'm interested in the connected components of $\operatorname{Hom}(\pi_1(S),\operatorname{SL}_n(\mathbb{R}))$ for $n$ at least $3$.
I know ...
- 443
7
votes
3
answers
210
views
Best source for classification of right-angled hyperbolic hexagons
A standard fact that underlies the Fenchel-Nielsen coordinates on Teichmuller space is the fact that for all triples $(a,b,c)$ of positive real numbers, there exists a unique hyperbolic hexagon whose ...
- 71
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310
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Integration à la Mirzakhani
Let $$
\gamma = \sum_i c_i \gamma_i
$$
be a multi-curve on a hyperbolic surface $S$. For any $f: \mathbb{R}^+ \to \mathbb{R}^+$ one can define $$
f_\gamma (X) = \sum_{\alpha \in \mathrm{Mod} . \gamma} ...
- 191
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votes
1
answer
153
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Two definitions of Teichmüller space: relative isotopy or not?
The definition of Teichmüller space on wikipedia via marked Riemann surfaces say that two markings are equivalent if the map $fg^{-1}$ is isotopic to a holomorphic diffeomorphism.
The definition on ...
- 1,457
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44
views
"Pushforward" of a universal curve by a map (Riemann surfaces)?
For a Riemann surface $X$ with a Beltrami form $\mu \in M(X),$ ($M(X)$ is the space of Beltrami forms on the Riemann surface), we can define the Riemann surface $X_\mu.$ In John H. Hubbard's ...
- 1,457
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1
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142
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Motivation for the definition of $L^p$ norm for quadratic and Beltrami differentials
According to Riemann surfaces, dynamics and
geometry
by C. McMullen (Course notes), the definition for a quadratic differential $\phi$ on a Riemann surface $X$ is given by
$$
\|\phi\|_p = \left(\...
- 1,457
2
votes
0
answers
53
views
Beurling’s extremality criterion for curves: two versions
I see Beurling’s extremality criterion at two places: the proof is almost identical, but the statement is very different. Below,
$$
\ell_\rho (\gamma) = \int_\gamma \rho(z) |dz|.
$$
"Extremal&...
- 1,457
3
votes
0
answers
168
views
Non commutative Teichmuller theory
Perhaps the first example in Teichmuller theory is the following proposition:
Proposition: Let $1<r<R$. Then two annular region $U_r=\{z\in \mathbb{C}\bigm|1<|z|<r\}$ and $U_R=\{z\in \...
- 205
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2
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Learning roadmap for Lorentzian geometry
I am asked the question in MSE, but did not get an answer. I hope that this question is appropriate for MOF.
I am interested in Hyperbolic Geometry and its significance in low dimensional geometry (...
- 31
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votes
1
answer
355
views
Paths $tg_1+(1-t)g_0$ in the moduli space of Riemann surfaces
Suppose $S$ is a smooth compact oriented surface without boundary. Let $g_0$ and $g_1$ be two smooth Riemannian metrics on $S$. Consider the interpolating path of metrics $g_t=g_1t+g_0(1-t)$. Recall ...
- 13.2k
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255
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References on Hyperbolic Geometry and Teichmuller Theory
I am asking a soft question here.
I am learning hyperbolic geometry on my own. Recently, I have completed the book "Fuchsian Groups" by Svetlana Katok. Also, I have background in Lee's three ...
user318929
2
votes
2
answers
224
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References on Riemann surfaces
I have asked the question in MSE, but did not get an answer.
I am asking a soft question here. I am interested in learning about Hyperbolic Geometry. I have read the book named "Fuchsian Groups&...
user318929
3
votes
0
answers
88
views
Clarifications about a proof of (the measurable Riemann) mapping theorem in Hubbard's book on Teichmuller theory,
On page 151 of Hubbard's book, the author is proving the following theorem( Prop.4.6.2 ):
Suppose $\mu$ is a real analytic function on a domain $U$ of $\mathbb{C}$. Then every $z \in U$ has a ...
- 41
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80
views
Relating different parametrizations of moduli space of Riemann surfaces
I would like to understand, as explicitly as possible, how different coordinates on the moduli space of Riemann surfaces are related:
On the one hand, there is a parametrization coming from hyperbolic ...
- 1,213
2
votes
0
answers
55
views
Thurston measure of Dehn-Thurston ball center at a multi curve
Given a surface of genus $g$ with $n$ singularities, and a decompostion of pair of pant $P=(p_1,...,p_{3g-3+n})$ one can give coordinate (called Dehn-Thurston coordinate) on the space of lamination $\...
- 191
2
votes
2
answers
181
views
Why a Teichmuller map is not a pseudo-anosov?
Let $X$ be a riemannian surface. Suppose $f:X\to X$ is a Teihmuller map with respect to a quadratic differential $q$ on $X$. This means that, if $q=dz^2$ in local coordinates in a neighborhood of ...
- 215
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35
views
flips on labelled fatgraphs and mapping classes
A fatgraph $G$ is a graph with a cyclic ordering of the edges at each vertex. A labelled fatgraph $(G,L)$ is a fatgraph together with a labelling $L$ of each edge. A labelled fatgraph spine $(G,L,e)$ ...
- 1,213
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votes
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214
views
Representation of the mapping class group in terms of flips on triangulations
$\DeclareMathOperator{\MCG}{\operatorname{MCG}}$Consider a bordered, punctured, orientable surface $S$. Associated to it there is its mapping class group $\MCG(S)$. One way to concretely think about ...
- 1,213
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votes
0
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67
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Harmonic maps versus Teichmuller maps between Riemann surfaces
Let $(X,\phi)$ be an element of Teichmuller space $\cal T_g$ and $q$ a (holomorphic) quadratic differential on $X$. Teichmuller geodesic flow gives a family of marked Riemann surfaces $(Y_t,\psi_t) = \...
- 245
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138
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When do the lengths of simple closed curves determine a hyperbolic surface?
Consider hyperbolic metrics on $\Sigma_g$ a closed orientable surface of genus $g$. Let $[\gamma_1] , \cdots, [\gamma_n]$ be a finite collection of isotopy classes of simple closed curves on $\Sigma_g$...
- 2,462
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0
answers
34
views
"Convergence" of bordered Riemann surfaces to a congruence surface
Let $\Gamma(N)$ be the principal congruence subgroup of level $N\geq 3$, $H$ the upper half-plane and $C(N)=H/\Gamma(N)$ be the corresponding Riemann surface. In his paper " Congruence Subgroups ...
- 21
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111
views
Well-definedness of marking a Riemann surface by diffeomorphisms in the context of Teichmüller spaces
In "An introduction to Teichmüler Theory" of Yoichi Imayoshi and Masahiko Taniguchi the Teichmüller space is defined as follows: fix a compact Riemann surface $R$ of genus $g$, a marking on ...
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0
answers
40
views
Whether or not two distinct points in Teichmuller space induce absolutely continuous volume forms on the unit tangent bundle of a surface?
Let $S$ be a closed orientable surface of genus greater than two. Let $g$ and $g'$ be metrics two of constant curvature. I guess we an think of these as two points in the Teichmüller space $\mathcal{T}...
- 215
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0
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70
views
Weil-Petersson metric with respect to covering
Let $S$ be a closed oriented surface of genus $g\geq 2$. Consider the Teichmuller space $T(S)$. Let $d_t$ be the Teichmuller metric and $d_{WP}$ be the Weil-Petersson metric on $T(S)$. Let $P:S_1\...
- 1,643
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2
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220
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Reference for openness of subspace of PSL(2,R) representation variety corresponding to Teichmüller space
$\DeclareMathOperator\PSL{PSL}\DeclareMathOperator\Hom{Hom}$Let $S$ be a compact oriented surface with nonempty boundary. There are two variants of Teichmuller space for $S$ you might consider:
The ...
- 61
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votes
1
answer
133
views
Number of Fuchsian groups with same trace field
Let $\Gamma,\Sigma\subset \mathrm{SL}_2({\mathbb R})$ be cocompact arithmetic subgroups. They are called commensurable in the wider sense, if there exists
$g\in \mathrm{SL}_2({\mathbb R})$, such that ...
user130903
4
votes
0
answers
95
views
Holomorphic maps on moduli space and Deformation theory
Let $\mathcal{M},\mathcal{F}$ be the classifiying spaces (i.e. complex manifolds) of two (possibly) different moduli problem. To give a map
$$f:\mathcal{M}\rightarrow \mathcal{F}$$
means that for each ...
- 3,103
4
votes
1
answer
576
views
The (measurable) Riemann mapping theorem
The Riemann mapping theorem says that a strict, nonempty open subset of the complex plane is conformally equivalent to the unit disk.
The measurable Riemann mapping theorem asserts the existence and ...
- 51
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answers
96
views
Isomorphism between two families of curves over the Teichmueller space
In his construction of the Teichmueller space of curves of genus $\geq 2$ Grothendieck states in Corollaire 2.4 that the map $$\underline{Isom}_S(X,Y) \xrightarrow{} S$$ is finite. The map represents ...
- 219
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91
views
Counting simple closed curves
I'm currently trying to understand how to count simple closed curves. I've been reading Alex Wright's survey (https://arxiv.org/pdf/1905.01753.pdf). However, I don't feel like I'm getting the big ...
- 3,103
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votes
1
answer
322
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Cutting up the Bring surface into six pairs of pants
The Bring sextic, with 120 automorphisms, is the numerically most symmetric compact Riemann surface of genus 4. To cut it up into six pairs of pants, we need to cut along nine disjoint geodesic loops....
- 363
7
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0
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150
views
Purely analytic proof of the Nielsen-Thurston classification theorem
I hope this question is appropriate for the site. I've been looking at the expositions of Bers' proof of the Nielsen-Thurston classification given in Hubbard's Teichmüller Theory
and Applications to ...
- 191
6
votes
1
answer
310
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Mirzakhani's hyperbolic method generalized to moduli space of stable maps
I've been learning about Mirzakhani's use of hyperbolic geometry to compute Weil-Petersson volumes of moduli space of curves, and the application to proving Virasoro constraints for a point. Why have ...
- 49
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votes
1
answer
94
views
Coordinates for Laminations: geometric versus shear
Let $S$ be an orientable surface with a triangulation T.
A lamination $\ell$ is a simple closed curve on $S$, up to isotopy. We will assume that $\ell$ is drawn in such a way that it intersects the ...
- 1,213
4
votes
1
answer
164
views
Explicit check of the invariance of the Weil-Petersson form
Using Fenchel-Nielsen coordinates, the Weil-Petersson metric can be written as
$\omega_{WP} = \sum_{i} d\ell_i \wedge d \tau_i,$
where $i$ is an index labelling the curves of a pants decomposition of ...
- 1,213
3
votes
1
answer
385
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Moduli, Teichmüller spaces and mapping class group of a sphere with four punctures
In the complex analytic setting, it is easy to see that the moduli space of a sphere with four punctures is $\mathcal{M}=\mathbb{CP}^1 / { 0,1,\infty }$, since I can use a Moebius transformation to ...
- 1,213
14
votes
3
answers
528
views
Does every $SL_2\mathbb{C}$ representation of a closed oriented surface extend over a compact oriented three-manifold?
Let $F$ be a compact oriented surface and $\rho:\pi_1(F)\rightarrow SL_2\mathbb{C}$ be a representation. Does there exist a compact oriented three-manifold $M$ with $\partial M=F$ and a homomorphism $...
- 3,384
2
votes
1
answer
188
views
What is the Teichmuller metric on the Teichmuller space of a closed surface of genus 1?
Howard Masur's research asserts that if $S_g$ is a closed surface of genus $g\geq2$, then the Teichmuller space $T(S_g)$ does not have nonpositive curvature. His proof relies on the existence of ...
- 273
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vote
0
answers
129
views
Area of balls on flat surfaces
Let $S$ be a closed surface of genus $g \geq 2$. Define $\mathrm{Flat}(S)$ to be the set of marked flat metrics on $S$ with cone angles $2\pi+k\pi$ for $k\geq 0$. It is well-known that these all come ...
- 167
3
votes
1
answer
80
views
Number of curves in an admissible system of Jordan curves on a surface
Consider a compact Riemann surface of genus $g\geq2$. An admissible system of Jordan curves is a finite collection of Jordan curves $\{\gamma_1,\cdots,\gamma_n\}$ such that
they are nonintersecting ...
- 273
3
votes
0
answers
74
views
How does one prove that the Teichmuller space of a closed Riemann surface of genus $\geq2$ is uniquely geodesic?
I am reading Masur's paper On a class of geodesic in Teichmuller space. He mentions that $T(S_0)$ where $S_0$ is a closed Riemann surface $g\geq2$ is straight, i.e. uniquely geodesic. It seems a well-...
- 273