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57 votes
7 answers
8k views

Maryam Mirzakhani's works

Maryam Mirzakhani has made several contributions to the theory of moduli spaces of Riemann surfaces. Mirzakhani was awarded the Fields Medal in 2014 for "her outstanding contributions to the dynamics ...
user avatar
44 votes
2 answers
5k views

Meaning/origin of Seiberg-Witten equations/invariants

Having now seen and "understood" (quotes necessary) the Seiberg-Witten equations on a closed oriented Riemannian 4-manifold $X$, I have no real understanding of where they came from. We take ...
Chris Gerig's user avatar
  • 17.5k
23 votes
1 answer
2k views

Do hyperKahler manifolds live in quaternionic-Kahler families?

A geometry question that I thought about more seriously a few years ago... thought it'd be a good first question for MO. I'm aware that there are a number of Torelli type theorems now proven for ...
Marty's user avatar
  • 13.3k
20 votes
3 answers
2k views

What is the DGLA controlling the deformation theory of a complex submanifold?

Let $X$ be a complex manifold, $Y\hookrightarrow X$ a complex compact submanifold. Let $T_{X/Y}$ denote the normal bundle of $Y$ in $X$, and $\mathcal{O}(T_{X/Y})$ its sheaf of holomorphic sections. ...
Braxton Collier's user avatar
13 votes
3 answers
1k views

DGLA or $L_{\infty}$-algebra controlling the deformation of Einstein metrics and instantons

As proposed by Quillen, Drinfeld, and Deligne and other important mathematicians, there is supposed to be a philosophy that, at least over a field of characteristic zero, assigns to every "deformation ...
Bilateral's user avatar
  • 2,816
13 votes
1 answer
564 views

What is the second fundamental form of moduli space?

Away from the hyperelliptic locus, the moduli of curves immerses in the moduli of principally polarized abelian varieties. The ambient space has a riemannian metric, so one can ask about the second ...
Ben Wieland's user avatar
  • 8,717
11 votes
1 answer
2k views

Seiberg-Witten theory on 4-manifolds with boundary

What generalizations of Seiberg-Witten theory to 4-manifolds with boundary do exist? I would be especially interested in theories which "behave good" under gluing along the boundary (comparable to ...
J Fabian Meier's user avatar
10 votes
2 answers
2k views

Floer homology and Invariants for Einstein Field Equations?

Motivation: There have been the instanton (anti-self dual connection) solutions to the Yang-Mills equation $d_A^\ast F_A=0$ which extremize the YM energy $\int_M|F_A|^2$, leading to the Donaldson ...
Chris Gerig's user avatar
  • 17.5k
10 votes
1 answer
706 views

Moduli space of flat connections of Lie group over a 2-torus

We know that the moduli space of SU($N$) principal bundle's flat connections over a torus, is equivalent to a complex projective space $\mathbb{P}^{N-1}$ Namely, $$ M_{\rm flat}=\mathbb{E} / {S}_N = \...
wonderich's user avatar
  • 10.5k
10 votes
0 answers
1k views

Roadmap to understanding Gromov's Non-squeezing theorem

I'm a graduate student starting out to venture into the areas of Symplectic Geometry/Topology, and was somewhat motivated by the essence of Gromov's non-squeezing theorem which in a sense made me feel ...
manav gaddam's user avatar
10 votes
0 answers
880 views

Central Yang-Mills connections, and flat connections with prescribed holonomy

Let $X$ be $\Sigma^g$ which is the Riemann surface of genus $g$, and consider a trivial $G$-bundle over it. 1) In this $2$-d setting, the space of Yang-Mills central connections is the set of ...
Bo Peng's user avatar
  • 1,525
9 votes
3 answers
1k views

Moduli spaces of connections as representation spaces

It is well known that the moduli space of flat connections over a closed manifold $M$ can be identified with the representation space $Hom(\pi_1(M), G) / G$. Furthermore, Atiyah and Bott (1983) ...
Tobias Diez's user avatar
  • 5,824
9 votes
3 answers
822 views

Geometric calculations using Grassmann variables

Physicists seem to get huge computational value by introducing Grassmann variables and Grassmann integration into differential geometric calculations. See: http://en.wikipedia.org/wiki/...
JoeG's user avatar
  • 91
8 votes
0 answers
291 views

Infinitely many nonempty Seiberg-Witten moduli spaces

The classic "finiteness" statement in Seiberg-Witten (SW) theory is that, for any smooth closed connected 4-manifold, there are only finitely many spin-c structures with nontrivial SW ...
Chris Gerig's user avatar
  • 17.5k
6 votes
2 answers
740 views

Flat metrics on $n$-toruses, their systoles, and the "shortest vector problem"

Apologies if this is too basic, but I haven't been able to find any info about the question. Is there anything known about the moduli space of flat metrics on an $n$-torus (i.e., $(S^1)^n$)? ...
Izaak Meckler's user avatar
6 votes
0 answers
155 views

Logarithmic Darboux theorem

Let $X$ be a smooth complex analytic manifold and $D$ be a normal crossing divisor. Suppose that there is a complex analytic logarithmic symplectic structure on $X$. Is there a Darboux like theorem ...
S.D.'s user avatar
  • 494
6 votes
0 answers
270 views

Varying a $J$-holomorphic sphere in a symplectic $4$-manifolds

I am certain that the following result holds, but was not able to find a reference. Do you know one? Or maybe you can give a short proof? Statement. Let $(M^4,\omega)$ be a compact symlectic manifold ...
aglearner's user avatar
  • 14.3k
5 votes
2 answers
623 views

When is differential geometry on moduli spaces possible (and productive)?

I will start out by saying I am not well-informed about moduli theory in the slightest. However, it is known that some moduli spaces (of algebro-geometric objects) have severe pathologies (Ex: Murphy'...
A. S.'s user avatar
  • 528
5 votes
1 answer
551 views

Relative logarithmic cotangent bundle

Let $\mathcal X \rightarrow S$ be a flat family of projective varieties over a discrete valuation ring $S$ such that the generic fibre $\mathcal X_{\eta}$ (say) is smooth projective variety and the ...
user avatar
5 votes
1 answer
1k views

Flat Principal Connections and Homotopy Groups?

I've come across a comment in a paper that hints at a relation between the set of (flat) connections for a principal bundle and the homotopy group of the base of the bundle. Can anyone tell me what ...
Abtan Massini's user avatar
4 votes
1 answer
344 views

Relative valuative criteria of properness for flat morphisms

Let $f: X\rightarrow S$ be a flat quasi-projective morphism, where $X$ is a smooth variety, and $S$ is a discrete valuation ring. Then we know that $f$ is proper morphism if and only if it satisfies ...
Bappa's user avatar
  • 153
4 votes
1 answer
139 views

The smoothness of solutions to the Hitchin self-dual equations within a stable orbit after Sobolev completion

First, let me introduce the background of the problem: While studying chapter 4 of the Hitchin's paper "THE SELF-DUALITY EQUATIONS ON A RIEMANN SURFACE", I encountered an issue. Hitchin ...
ShuoW's user avatar
  • 41
4 votes
1 answer
229 views

Orientability of moduli space and determinant bundle of ASD operator

Setting In instanton gauge theory, given a $G$-principal bundle $P\to X^4$, the orientability of the moduli space of ASD connections $$\mathcal{M}_k = \{A \in L^{2}_{k}(X, \Lambda^1 \otimes\mathrm{...
Overflowian's user avatar
  • 2,533
4 votes
0 answers
109 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 ...
curious math guy's user avatar
4 votes
0 answers
185 views

Moduli space of complex Tori [duplicate]

Is there any explicit computation for the Weil-Petersson metric on moduli space of Tori of complex dimension n?
user avatar
3 votes
1 answer
285 views

The fixed points set of the actions of $\mathbb{C}^*$ and $S^1$ on the Higgs bundle moduli space

Let $\mathcal{M}_{d}(G)$ be the moduli space of $G$-Higgs bundles. $\mathcal{M}_{d}(G)$ have a non-trivial $\mathbb{C}^{*}$-holomorphic action by multiplication of the Higgs field, $$ z\cdot (E, \...
Leonardo Schultz's user avatar
3 votes
1 answer
465 views

de-Rham moduli space over a compact Riemann surface

Let $X$ be a smooth projective curve over $\mathbb C$ and $M_{dR}$ denote the moduli space of stable $\Lambda$-connections of fixed rank and degree $0$. Is it known whether $M_{dR}$ is a smooth ...
user131608's user avatar
3 votes
1 answer
959 views

Isomorphism classes of line bundles with connections

Isomorphism classes of line bundles over a scheme $X$ are described by the Picard group $Pic(X)$. Now there is a paper that describes the moduli space of line bundles with connections. This paper is ...
Marion's user avatar
  • 587
3 votes
1 answer
578 views

Hilbert Mumford Criterion

Let $V$ be a vector space over a field $k$. Consider the natural action of $SL(V)$ on Sym$^2 V$. Is there a easy formulation of Hilbert Mumford Criterion for semi-stablity of the points of Sym$^2 V$ ...
user avatar
3 votes
0 answers
233 views

Kodaira-Spencer map in logarithmic geometry

Can anyone provide a reference for the Kodaira-Spencer map in the logarithmic geometry setting?
S.D.'s user avatar
  • 494
3 votes
0 answers
152 views

Riemannian metric over moduli space of Riemann spheres with n punctures

In the paper `Tessellations of moduli spaces and the mosaic operad' by Devadoss (https://arxiv.org/pdf/math/9807010.pdf), on page 5-6, the author identifies hyperbolic planar tree space (or the ...
Ali Gato's user avatar
3 votes
0 answers
150 views

Cubic 3-folds/genus 4 curves as an example of Kähler-Einstein moduli?

Is it currently known whether or not any the standard ball quotient models (As introduced in Allcock-Carlson-Toledo, Laza, Yokoyoma,... is an example of a moduli space of K-polystable Fano varieties (...
Nati's user avatar
  • 1,981
3 votes
0 answers
209 views

Integrations of Ricci curvature of the Weil-Petersson metric on the moduli space of varieties of general type is a rational numbers?

It is known that the integrations of Ricci curvature of the Weil-Petersson metric on the moduli space of Calabi-Yau varieties is a rational numbers My question is about the moduli space of ...
user avatar
2 votes
1 answer
380 views

Moduli of stable bundles - analytic approach

Consider a compact Riemann surface $X$ of genus $\ge 2$, and consider the set $M$ of stable holomorphic vector bundles of rank $n$ and degree $d$ on $X$, up to isomorphism. At that point, one states ...
Sasha's user avatar
  • 5,562
2 votes
1 answer
290 views

On the stack of semistable curves

This is a question related to Semistable curves of genus $g\geq 2$ form an Artin algebraic stack in the etale topology? Let $\mathcal C\rightarrow \mathcal M^{ss}_g$ be the universal curve over the ...
S.D.'s user avatar
  • 494
2 votes
1 answer
271 views

Canonical connection on $\mathcal{A}\times X$

Let $E\rightarrow X$ be a vector bundle and let $\mathcal{A}$ denote the space of connections on $E$. Pulling back $E$ by the second projection we obtain a vector bundle $\mathbb{E}=p_2^*E\rightarrow ...
BinAcker's user avatar
  • 789
2 votes
2 answers
231 views

Nahm's equations with poles and conservation of characteristic polynomial

In "Supersymmetric Boundary Conditions in N=4 Super Yang-Mills Theory" Nahm's equations are studied in Section 3. In particular, it is explained that their moduli space of solutions, $\...
Mtheorist's user avatar
  • 1,155
2 votes
1 answer
204 views

Metric on moduli space of semistable principal G-bundles on curves

Let $X$ be an irreducible smooth projective curve over $\mathbb{C}$. Let $G$ be a connected reductive linear algebraic group over $\mathbb{C}$. Let ${\rm M}_{G,X}$ be the moduli space of semistable ...
user124771's user avatar
2 votes
1 answer
1k views

Moduli space of flat connections over a torus

Let us fix a principal bundle $G\hookrightarrow P\to T^{2}$, where $T^{2}$ is a torus. Is the moduli space of flat connections on $P$ known? At least, it is known for some particular gauge groups, ...
Bilateral's user avatar
  • 2,816
2 votes
1 answer
612 views

pullback of poincare bundle

Let $X$ be a smooth curve and ${x,y}$ are two smooth points. Let $J_X$ be the jacobian of X i.e, the variety which parametrizes the degree 0 line bundles on X and let $\mathcal{P}$ is the poincare ...
Kumar's user avatar
  • 151
2 votes
0 answers
170 views

A silly doubt on Log structures

Let $X=\operatorname{Spec} A$ be an affine variety. Consider the log structure given by $\mathbb N\rightarrow A$ which sends $1\mapsto 0$. Also consider the log structure $\mathbb N^r \rightarrow A$ ...
S.D.'s user avatar
  • 494
2 votes
0 answers
279 views

Symplectic form on moduli space of connections

Let $M$ be the moduli space of flat $GL(n,\mathbb{C})$ connections on a compact oriented surface, and $\alpha$ the natural symplectic form on it. Is there any known construction of a bundle with a ...
Grey's user avatar
  • 21
1 vote
1 answer
351 views

GIT quotients of open subsets

Let X be a projective variety on with a action of reductive group G. Let L be a G Linearised ample line bundle on X. Let U be a G stable open subset of X. Let $U^{ss}:=X^{ss}\cap U$. Is it true that $...
user avatar
1 vote
2 answers
912 views

Connections on the Hodge bundle?

Let $\mathcal{M}_g$ be the moduli space of curves of genus $g$. Consider the holomorphic bundle $\mathcal{H}^k\rightarrow\mathcal{M}_g$ whose fiber over a curve $C\in\mathcal{M}_g$ is the space of ...
Xin Nie's user avatar
  • 1,804
1 vote
0 answers
73 views

Local Chart for Teichmuller Space as A Manifold

Let $(R,p_1,…,p_n)$ be a Compact Riemann surface of genus $g$ with $n$ marked points. Its deformation space is $H^1(R, K_R^{-1}\otimes\mathcal{O}(-p_1),…,\mathcal{O}(-p_n))$. From Riemann-Roch theorem,...
CharlieHo's user avatar
1 vote
0 answers
86 views

Banach manifold structure on the moduli space of hybrid trajectories

I am reading the paper "On the Floer homology of cotangent bundles", (arXiv link) , by Abbondandolo and Schwarz and in page $35$ to define the isomorphism between the Morse complex and the ...
Someone's user avatar
  • 791
1 vote
0 answers
114 views

On stability of coherent sheaves over a quasiprojective variety

Let $X$ be a smooth projective variety of dimension $n$ and $L$ be an ample line bundle on $X$. For any coherent sheaf $E$, one can define the first Chern class $C_1(E)$ and degree of $E$ to be $C_1(E)...
user avatar
1 vote
0 answers
355 views

On logarithmic schemes

I have two questions on logarithmic schemes Can we explicitly construct a chart for any coherent logarithmic scheme? By definition of coherence it must have a chart but given a coherent sheaf of ...
S.D.'s user avatar
  • 494
1 vote
0 answers
501 views

The Deligne-Mumford Compactification for Closed Surfaces

I am reading this note on super-Riemann surfaces. In the second paragraph of section 7.4.1 (page 87), there is a statement that I am trying to understand: The compactified moduli space of closed ...
QGravity's user avatar
  • 989
1 vote
0 answers
97 views

A genericity argument on family of disconnected holomorphic curves

Let $(W, \lambda)$ be an exact cobordism from $(M_+, \lambda_+)$ to $(M_-, \lambda_-)$ and $\overline{W}$ be the usual symplectic completion of $W$. Let $\mathcal{M}(J)$ be the module space of all ...
trick1234's user avatar
  • 185