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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

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48 results for Riemann extensions

We study the properties of Modified Riemann extensions evolving under Ricci flow. We obtain the necessary and sufficient condition for modified Riemann extension under Ricci flow to stay as modified Riemann extension. We also discuss the properties of the curvature tensors under Ricci flow.

2015-05-03abs ↗pdf ↗

In this paper the rate relations of Riemann, conformal, conharmonic and Weyl curvature tensors under Yamabe flow are studied. Modified Riemann extensions under Yamabe flow is discussed. The paper ends with remarks on some standard metrics.

2019-07-08abs ↗pdf ↗

Krein's formula for conic Laplacians on compact Riemann surfaces

problem Establishing Krein's formula for self-adjoint extensions of conic Laplacians on compact Riemann surfaces
method Using finite-dimensional symplectic space of critical asymptotic boundary data
result Deriving a trace identity for the resolvent difference and proving a comparison formula for the positive-spectrum zeta determinants

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…

2015-11-16abs ↗pdf ↗

The subject of this paper is Beurling's celebrated extension of the Riemann mapping theorem \cite{Beu53}. Our point of departure is the observation that the only known proof of the Beurling-Riemann mapping theorem contains a number of gaps which seem inherent in Beurling's geometric and approximative approach. We provi…

2009-06-17abs ↗pdf ↗

Effective field theories with explicit Lorentz violation are intimately linked to Riemann-Finsler geometry. The quadratic single-fermion restriction of the Standard-Model Extension provides a rich source of pseudo-Riemann-Finsler spacetimes and Riemann-Finsler spaces. An example is presented that is constructed from a …

2011-04-28abs ↗pdf ↗

Riemann extension for the anti Mach metric is derived, the solution of geodesic equations for the extended space are given, some properties for the extended space was studied and compared with the basic space and the constructions of a translation surface for the anti Mach metric in four dimension is established.

2014-11-18abs ↗pdf ↗

Study on null-projectability of Levi-Civita connections in neutral metrics.

problem Characterizing projectability of Levi-Civita connections along null parallel distributions.
method Analyzing projectability of torsion-free connections along foliations on manifolds, focusing on neutral metric signatures and mid-dimensional distributions.
result Extension of Patterson and Walker's Riemann extension metrics to null parallel distributions of any dimension.

New topological Riemann-Roch theorem for circle fibrations.

problem Topological Riemann-Roch theorem for complex line bundles on circle fibrations.
method Construction of central extensions and application to algebraic K-theory.
result Equality of specific cohomology elements in the third cohomology group.

Study on zeros of Gaussian sections on semipositive line bundles on punctured Riemann surfaces.

problem Distribution of zeros of Gaussian sections on semipositive line bundles.
method Analysis of Bergman kernels and random zeros in high tensor powers.
result Equidistribution, large deviation estimates, central limit theorem, and number variances for zeros in the semi-classical limit.

Extends mean curvature to surfaces in Riemann-Cartan geometry with torsion.

problem Addressing surfaces in Riemann-Cartan geometry with nontrivial torsion.
method Introducing a complex-valued 2-form associated with the torsion, which interacts with other geometric concepts.
result Complex-valued mean curvature quantity interacts with Hopf differential and Gauss map.

Some examples of three-dimensional metrics of constant curvature defined by solutions of nonlinear integrable differential equations and their generalizations are constructed. The properties of Riemann extensions of the metrics of constant curvature are studied. The connection with the theory of normal Riemann spaces a…

2005-05-18abs ↗pdf ↗

In "The Yang-Mills equations over Riemann surfaces", Atiyah and Bott studied Yang-Mills functional over a Riemann surface from the point of view of Morse theory. We generalize their study to all closed, compact, connected, possibly nonorientable surfaces. We introduce the notion of "super central extension" of the fund…

2006-05-22abs ↗pdf ↗

Constructs a map from stable extensions to irreducible metrics on Riemann surfaces.

problem Understanding and constructing cone spherical metrics on Riemann surfaces.
method Using the theory of indigenous bundles, the construction involves developing maps and stable extensions of two line bundles.
result Generically injective map from stable extensions to irreducible metrics, with properties about effective divisors.

Consider a smooth manifold with a smooth metric which changes bilinear type from Riemann to Lorentz on a hypersurface ΣΣ with radical tangent to ΣΣ. Two natural bilinear symmetric forms appear there, and we use it to analyze the geometry of ΣΣ. We show the way in which these forms control the smooth extensibility ov…

2003-06-10abs ↗pdf ↗

The Kazdan-Warner problem is solved for Riemann surfaces with smooth boundaries.

problem Realizing smooth functions as Gaussian and geodesic curvatures on compact Riemann surfaces.
method Existence results of Brezis-Merle type equations and uniformization theorem extension.
result Any smooth function on compact Riemann surface with smooth boundary can be realized as a Gaussian curvature function and any on the boundary as a geodesic curvature function.

The paper develops a Galois theory for cluster algebras and Riemann surfaces.

problem Building a correspondence between cluster subalgebras and automorphism groups.
method Introducing Galois-like extensions and automorphism groups for cluster algebras.
result Conditions for Galois-like extensions and properties of cluster automorphism groups.

Study finds existence and non-uniqueness of cone spherical metrics on compact Riemann surfaces.

problem Existence and non-uniqueness of cone spherical metrics with prescribed singularities.
method Utilizing polystable extensions of line bundles, the study establishes three primary results concerning these metrics.
result Existence of multiple irreducible and reducible cone spherical metrics for certain effective divisors.

The period is a classical complex analytic invariant for a compact Riemann surface defined by integration of differential 1-forms. It has a strong relationship with the complex structure of the surface. In this chapter, we review another complex analytic invariant called the harmonic volume. It is a natural extension o…

2016-02-06abs ↗pdf ↗

Study Schiffer operators on Riemann surfaces, linking conformal and topological invariants.

problem Investigate Schiffer operators on Riemann surfaces and their connections to conformal and topological invariants.
method Develop calculus for Schiffer and Cauchy operators, derive index theorems, and characterize kernels and images.
result Derive index theorems for Schiffer operators, connecting conformal invariants to topological invariants.

The paper calculates determinants for Laplacians on spinor bundles over surfaces with flat metrics.

problem Calculating determinants for Laplacians on spinor bundles over surfaces with flat metrics.
method Explicit expressions for determinants of self-adjoint extensions of Laplacians using Bergman tau-function and theta-constants.
result An explicit expression for the determinant of the Szegö extension and comparison formulas for different extensions.

Regularized zeta function for polyhedra calculated from Riemann surface invariants.

problem Calculating a spectral invariant for polyhedra using zeta function regularization.
method Holomorphic invariants and conical points of the metric, sewing two polyhedra, self-adjoint extensions.
result Explicit expression for spectral invariant through Riemann surface invariants.

Harmonic maps from Riemann surfaces arise from a conformally invariant variational problem. Therefore, on one hand, they are intimately connected with moduli spaces of Riemann surfaces, and on the other hand, because the conformal group is noncompact, constitute a prototype for the formation of singularities, the so-ca…

2017-10-04abs ↗pdf ↗

We consider the problem of extending a conformal metric of negative curvature, given outside a neighbourhood of 0 in the unit disk $\DD$, to a conformal metric of negative curvature in $\DD$. We give conditions under which such an extension is possible, and also give obstructions to such an extension. The methods we us…

2002-02-25abs ↗pdf ↗

Motivated by the supersymmetric extension of Liouville theory in the recent physics literature, we couple the standard Liouville functional with a spinor field term. The resulting functional is conformally invariant. We study geometric and analytic aspects of the resulting Euler-Lagrange equations, culminating in a blo…

2005-11-09abs ↗pdf ↗

The level set of an elliptic function is a doubly periodic point set in C. To obtain a wider spectrum of point sets, we consider, more generally, a Riemann surface S immersed in C^2 and its sections (``cuts'') by C. We give S a crystallographic isometry in C^2 by defining a fundamental surface element as a conformal ma…

1999-04-03abs ↗pdf ↗

Quadratic differentials on Riemann surfaces uniquely determine foliations.

problem Understanding the relationship between quadratic differentials and foliations on Riemann surfaces.
method Extending prior results to arbitrary Fuchsian groups, analyzing measured foliations and their Dirichlet integrals.
result A finite-area holomorphic quadratic differential uniquely determines a horizontal foliation on a Riemann surface.

Study pseudo-laplacians and ζ(1) for spinor bundles over Riemann surfaces.

problem Analyzing self-adjoint extensions of Dolbeault Laplacians on Riemann surfaces.
method Defined ζζ-regularized determinants, introduced Robin mass, derived comparison formulas.
result Explicit expressions for Robin mass in spinor bundles and scalar cases.

The paper extends sequences while preserving statistical properties using a mixture model.

problem Extending sequences while retaining their statistical properties.
method Auto-regressive Sequence Extension Mixture Model (SEMM) using deep learning.
result The mixture model outperforms traditional neural networks in sequence extension with statistical property retention.

We consider the local analytic behavior for a family of holomorphic differentials on a family of degenerating annuli. Three results and discussion are presented. The first is the normal families Lemma 1. The second is an isomorphism of sheaves, formula (3), giving a direct description of families of regular kk-differe…

2011-08-16abs ↗pdf ↗

Improved method for numerical conformal mappings on complex domains.

problem Accurate and efficient computation of conformal mappings on multiply connected domains.
method Generalization and refinement of the conjugate function method using high-order finite element methods.
result Achieved accurate and efficient construction of boundary values for multiply connected domains.

Paper derives a formula for the determinant of Dirichlet-to-Neumann operator on Riemann surfaces.

problem Bounding asymptotics of a conformal invariant under degeneration of Riemann surfaces.
method Meyer-Vietoris formula, gluing, height function on moduli space, properness of height function, Steklov isospectral metrics, Laplacian with Dirichlet/Neumann boundary conditions.
result Properness of height function on moduli space of genus zero hyperbolic surfaces implies compactness theorem for Steklov isospectral metrics.

We continue our study, initiated in our earlier paper, of Riemann surfaces with constant curvature and isolated conic singularities. Using the machinery developed in that earlier paper of extended configuration families of simple divisors, we study the existence and deformation theory for spherical conic metrics with s…

2019-06-24abs ↗pdf ↗

In this note we revisit the notion of conformal barycenter of a measure on $\SS^n$ as defined by Douady and Earle in Acta Math. Vol 157, 1986. The aim is to extend rational maps from the Riemann sphere $\Cbar\isom\SS^2$ to the (hyperbolic) three ball $\BB^3$ and thus to $\SS^3$ by reflection. The construction which was…

2011-02-07abs ↗pdf ↗

This paper introduces complex Chern-Simons bundles in families setting and proves their crystalline nature.

problem Characterizing projective structures of Riemann surfaces and establishing holomorphic torsion formulas.
method Develops a formalism for direct images of characteristic classes, uses deformation theory of harmonic maps, and relies on non-abelian Hodge theory.
result Establishes the crystalline nature of the relative complex Chern-Simons bundle and its holomorphic extension.

In this paper, we extend Deligne's functorial Riemann-Roch isomorphism for hermitian holomorphic line bundles on Riemann surfaces to the case of flat, not necessarily unitary connections. The Quillen metric and star-product of Gillet-Soule are replaced with complex valued logarithms. On the determinant of cohomology si…

2016-03-18abs ↗pdf ↗

Convexity properties of Weil-Petersson geodesics on the Teichmüller space of punctured Riemann surfaces are investigated. A normal form is presented for the Weil-Petersson Levi-Civita connection for pinched hyperbolic metrics. The normal form is used to establish approximation of geodesics in boundary spaces. Considera…

2007-09-16abs ↗pdf ↗