Study harmonic metrics on Higgs bundles on non-compact Riemann surfaces.
problem Proving the existence and uniqueness of harmonic metrics on Higgs bundles.
method Analyzing Higgs bundles equipped with a non-degenerate symmetric pairing on non-compact Riemann surfaces.
result Proving the existence and uniqueness of compatible harmonic metrics under certain conditions.
Complete solutions found for Toda equations on non-compact surfaces.
problem Solving Toda equations on non-compact Riemann surfaces.
method Introduced complete solutions and proved existence and uniqueness using Toda equations and harmonic bundle techniques.
result Existence and uniqueness of complete solutions to Toda equations on non-compact Riemann surfaces.
Every open Riemann surface can be triangulated with equilateral triangles.
problem The structure and triangulation of Riemann surfaces.
method Constructing a holomorphic branched covering to the Riemann sphere and glueing together equilateral triangles.
result Every open Riemann surface can be equilaterally triangulated.
Harmonic metrics are established for SO0(n,n)-Higgs bundles on non-compact hyperbolic surfaces.
problem Establishing harmonic metrics for SO0(n,n)-Higgs bundles.
method Using canonical line bundle and holomorphic differentials, the existence and uniqueness of harmonic metrics are proven.
result Existence and uniqueness of harmonic metrics compatible with SO0(n,n) structure on non-compact hyperbolic surfaces.
The topological type of a non-compact Riemann surface is determined by its ends space and the ends having infinite genus. In this paper for a non-compact Riemann Surface Sm,s with s ends and exactly m of them with infinite genus, such that m,s∈N and 1<m≤s, we give a precise description of t…
Let S be a compact hyperbolic Riemann surface of genus g≥2. We call a systole a shortest simple closed geodesic in S and denote by sys(S) its length. Let msys(g) be the maximal value that sys(⋅) can attain among the compact Riemann surfaces of genus g. We call a (global…
In this paper, we develop a loop group description of harmonic maps F:M→G/K ``of finite uniton type", from a Riemann surface M into inner symmetric spaces of compact or non-compact type. This develops work of Uhlenbeck, Segal, and Burstall-Guest to non-compact inner symmetric spaces. To be mo…
We develop an asymptotic expansion of the spectral measures on a degenerating family of hyperbolic Riemann surfaces of finite volume. As an application of our results, we study the asymptotic behavior of weighted counting functions, which, if M is compact, is defined for w≥0 and T>0 by $$N_{M,w}(T) = \sum\…
Using Morse-theoretic techniques, we show that the moduli space of U*(2n)-Higgs bundles over a compact Riemann surface is connected.
We use meromorphic quadratic differentials with higher order poles to parametrize the Teichmüller space of crowned hyperbolic surfaces. Such a surface is obtained on uniformizing a compact Riemann surface with marked points on its boundary components, and has non-compact ends with boundary cusps. This extends Wolf's pa…
We prove that any two finite-area non-compact hyperbolic Riemann surfaces S and T have finite covers that are arbitrarily close in the normalized Weil-Petersson metric, where we normalize by dividing the square of the metric by the area of the surface. In the case where T is the modular surface this reduces to showing …
The Loch Ness Monster admits many regular dessins d'enfants and different holomorphic structures.
problem Classical theory of dessins d'enfants on compact surfaces extended to non-compact surfaces.
method Study of infinite genus surfaces and their connections to Riemann surfaces.
result The Loch Ness monster admits infinitely many regular dessins d'enfants.
The paper studies spaces of non-compact real algebraic curves and their uniformisation.
problem Understanding the spaces of non-compact real algebraic curves and their uniformisation.
method Construction of spaces of non-compact real algebraic curves and description of their connected components using Fuchsian groups.
result Any connected component of the spaces of non-compact real algebraic curves is homeomorphic to a quotient of a finite-dimensional real vector space by a discrete group.
Paper develops a new method for harmonic maps into symmetric spaces.
problem Tackles harmonic maps of finite uniton number into symmetric spaces.
method Uses loop group description and DPW theory to transform results.
result Establishes a 1-1 relation between harmonic maps and normalized potentials.
The paper explores harmonic maps and their properties in symmetric spaces.
problem Understanding harmonic maps in symmetric spaces.
method Discussion of associated family of harmonic maps from Riemann surfaces into symmetric spaces.
result Comparison and conjecture on harmonic maps and totally symmetric harmonic maps.
Defines new invariants for Riemann-Finsler manifolds, generalizing Preissman's theorem.
problem Finding metrics with negative sectional curvature on compact products.
method Defining a Q-valued deformation invariant and using it to generalize Preissman's theorem. result First and mostly sharp generalizations of Preissman's theorem on non-existence of negative sectional curvature metrics.
Unified rigidity theorem for cyclic and alternating surfaces.
problem Infinitesimal rigidity of equivariant minimal maps.
method Unified Lie-theoretic framework connecting cyclic surfaces and cyclic harmonic bundles.
result Infinitesimal rigidity for irreducible cyclic surfaces under various variations.
Classifies solutions of Toda equations near singularities.
problem Classifying solutions of Toda equations near singularities.
method Analyzes meromorphic and essential singularities of r-differentials. result Classifies all solutions on C for finite sums of exponentials of polynomials. We consider an inverse problem associated with some 2-dimensional non-compact surfaces with conical singularities, cusps and regular ends. Our motivating example is a Riemann surface M=Γ\H2 associated with a Fuchsian group of the 1st kind Γ containing parabolic elements. M is t…
Harmonic metrics on Higgs bundles over non-compact hyperbolic surfaces are studied.
problem Existence and uniqueness of harmonic metrics on Higgs bundles over non-compact hyperbolic surfaces.
method Defined Higgs bundles in the Hitchin section, used harmonic metrics and real structures.
result Existence and uniqueness of harmonic metrics on Higgs bundles over non-compact hyperbolic surfaces.
The paper develops mathematical models for neural networks using non-compact symmetric spaces.
problem Developing mathematical models for neural networks using non-compact symmetric spaces.
method Introducing layers modeled as non-compact symmetric spaces, each mapped onto the next by solvable group homomorphisms.
result Group theoretical construction of separators for all non-compact symmetric spaces and uniformization of specific surfaces.
In this article we introduce a definition for the moduli space of equivariant minimal immersions of the Poincaré disc into a non-compact symmetric space, where the equivariance is with respect to representations of the fundamental group of a compact Riemann surface of genus at least two. We then study this moduli space…
Paper examines conditions making Riemann solitons trivial and estimates their scalar curvature.
problem Conditions making Riemann solitons trivial and scalar curvature estimates.
method Analyzes compactness and behavior at infinity of gradient fields.
result Obtains scalar curvature estimates for certain Riemann solitons.
The theory of Hitchin systems is something like a "global theory of Lie groups", where one works over a Riemann surface rather than just at a point. We'll describe how one can take this analogy a few steps further by attempting to make precise the class of rich geometric objects that appear in this story (including the…
Classifies π1-injective maps between non-compact surfaces.
problem Characterizing maps with injective fundamental groups.
method Proper homotopy classification of maps.
result All π1-injective proper maps are classified. Strong rigidity proven for non-compact surfaces.
problem Proving rigidity of non-compact surfaces.
method Generalized result showing proper homotopy to homeomorphism.
result All non-compact orientable surfaces, except plane and punctured plane, are topologically rigid.
A classical result of Sampson and Schoen-Yau in 1978 states that every diffeomorphism between compact hyperbolic Riemann surfaces is homotopic to an harmonic diffeomorphism. As conjectured by Schoen in 1993 and partially proved by Wan in 1992 and Tam-Wan in 1995, we prove in this article that this theorem generalizes t…
Let (E,D,P) be a flat vector bundle with a parabolic structure over a punctured Riemann surface, (M,g). We consider a deformation of the harmonic metric equation which we call the Poisson metric equation. This equation arises naturally as the dimension reduction of the Hermitian-Yang-Mills equation for holomorphic vect…
Goldman bracket distinguishes surface homeomorphisms.
problem Characterizing homeomorphisms between non-compact surfaces.
method Using the Goldman bracket to distinguish homeomorphisms.
result A homotopy equivalence is a homeomorphism if it preserves the Goldman bracket.
Paper calculates homotopy types of non-compact surfaces using groupoids.
problem Computing homotopy types of non-compact foliated surfaces.
method Application of van Kampen theorem for groupoids.
result Computation of homotopy types for specific non-compact surfaces.
The paper studies how hyperbolic surfaces degenerate along harmonic map rays.
problem The degeneration of hyperbolic surfaces along harmonic map rays.
method Using Teichmüller space and holomorphic quadratic differentials, the authors show convergence of rescaled distance functions to the intersection number with a vertical measured foliation.
result Hyperbolic surfaces along the ray converge to the dual R-tree of the vertical measured foliation in the sense of Gromov-Hausdorff.
Maps between non-compact surfaces can have geometric kernels under certain conditions.
problem Understanding when maps between non-compact surfaces have geometric kernels.
method Using Brown's proper fundamental group to establish sufficient conditions for geometric kernels.
result Characterization of conjugacy classes in the proper fundamental group and sufficient conditions for geometric kernels.
Riemann surfaces are two-dimensional manifolds with a conformal class of metrics. It is well known that the harmonic action functional and harmonic maps are tools to study the moduli space of Riemann surfaces. Super Riemann surfaces are an analogue of Riemann surfaces in the world of super geometry. After a short intro…
A method to describe Riemann surfaces using graph profiles is proposed.
problem Describing Riemann surfaces in a graph-theoretic framework.
method Graph profiles to represent Riemann surfaces, establishing necessary and sufficient conditions for their existence.
result A criterion for the existence of Riemann surfaces with a given signature.
Bonahon's method for compactifying Teichmüller space extended to non-compact surfaces.
problem Compactifying Teichmüller space for non-compact finite area surfaces.
method Using geodesic currents, extending Bonahon's construction.
result The method applies to surfaces of finite area.
Generalizes Riemann-Hilbert correspondence for curved local systems.
problem Higher Riemann-Hilbert correspondence with scalar curvature.
method Equivalence of dg-categories of curved local systems, graded vector bundles, and representations.
result Equivalence of dg-enhancements of twisted sheaves categories.
We derive an analytic formula for the hydrodynamic Green function and the Robin function on every orientable surface admitting a hydrodynamic Killing vector field. Closed-form expressions are provided for all fourteen canonical Riemann surfaces, covering both compact and non-compact cases; the formulae satisfy the slip…
Study Liouville action for harmonic maps between Riemann surfaces.
problem Optimizing harmonic maps between Riemann surfaces.
method Derive variational formula for Liouville action.
result Found variational formula for harmonic diffeomorphisms.
In this paper, we address the following question: What does a typical compact Riemann surface of large genus look like geometrically? We do so by constructing compact Riemann surfaces from oriented 3-regular graphs. The set for such Riemann surfaces is dense in the space of all compact Riemann surfaces, namely Belyi su…
The underlying even manifold of a super Riemann surface is a Riemann surface with a spinor valued differential form called gravitino. Consequently infinitesimal deformations of super Riemann surfaces are certain infinitesimal deformations of the Riemann surface and the gravitino. Furthermore the action functional of no…
This paper studies non-compact Ricci surfaces with catenoidal ends.
problem Characterizing non-compact Ricci surfaces with catenoidal ends.
method Using Weierstrass data and minimal immersion techniques.
result Classification and existence results for positive genus Ricci surfaces.
Study curve shortening flow on Riemann surfaces with conic singularities.
problem Analyzing curve shortening flow on surfaces with conic singularities.
method Generalized Huisken's comparison function to Riemann surfaces and surfaces with conic singularities. Reproofed Gage-Hamilton-Grayson theorem. Proved CSF can't touch conic singularities with cone angles ≤ π.
result CSF can't touch conic singularities with cone angles ≤ π for embedded simple closed curves.
The Seiberg-Witten equation with multiple spinors generalises the classical Seiberg-Witten equation in dimension three. In contrast to the classical case, the moduli space of solutions M can be non-compact due to the appearance of so-called Fueter sections. In the absence of Fueter sections we define a sign…
In this paper we study the smooth moduli space of closed Riemann surfaces. This smooth moduli is an infinite cover of the usual moduli space Mg of closed Riemann surfaces, and is identified with the Schottky space of rank g. The main theorem of the paper is: Closed Riemann surfaces are uniformizable by S…
Criterion found for Teichmüller extremal maps on infinite Riemann surfaces.
problem Finding necessary and sufficient conditions for Teichmüller extremal maps.
method Established a criterion for Teichmüller-type extremal maps.
result Criterion for Teichmüller extremal maps on infinite Riemann surfaces.
New invariant for Riemann surfaces connects to moduli space classes.
problem Understanding Riemann surface invariants and their relationships.
method Introducing a twisted version of the Kawazumi-Zhang invariant and relating it to other classes.
result The new invariant connects to the first Mumford-Morita-Milller class on the moduli space.
New gauge-theoretic construction of 4D hyperkähler ALE spaces.
problem Classifying and understanding 4D hyperkähler ALE spaces.
method Gauge-theoretic construction of 4D hyperkähler ALE spaces via solutions to a system of equations for a pair of a connection and a section of a vector bundle over an orbifold Riemann surface, modulo a gauge group action.
result A new gauge-theoretic interpretation of Kronheimer's classification of 4D hyperkähler ALE spaces.
Study on existence of balanced metrics on non-Kähler manifolds.
problem Existence of balanced metrics on non-Kähler complex manifolds.
method Analyzes obstructions and constructs examples, focusing on compact quotients of Lie groups.
result Proves non-existence on certain non-Kähler complex parallelizable manifolds and solvmanifolds.