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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.

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128257385513 · May 202619922001200920172026
48 results for universal structure

We show that the canonical contact structure on the link of a normal complex singularity is universally tight. As a corollary we show the existence of closed, oriented, atoroidal 3-manifolds with infinite fundamental groups which carry universally tight contact structures that are not deformations of taut (or Reebless)…

2010-05-13abs ↗pdf ↗

We study deformation of spherical CRCR circle bundles over Riemann surfaces of genus > 1. There is a one to one correspondence between such deformation space and the so-called universal Picard variety. Our differential-geometric proof of the structure and dimension of the unramified universal Picard variety has its own…

1998-07-08abs ↗pdf ↗

Building on the universal covering group of the general linear group, we introduce the composite spinor bundle whose subbundles are Lorentz spin structures associated with different gravitational fields. General covariant transformations of this composite spinor bundle are canonically defined.

1997-05-21abs ↗pdf ↗

The paper studies moduli spaces of non-smooth metric structures with non-negative Ricci curvature.

problem Understanding moduli spaces of non-smooth metric structures with non-negative Ricci curvature.
method Relating convergence of RCD(0,N)-structures to their lifts, constructing Albanese and soul maps, proving their continuity, and constructing examples.
result Construction of moduli spaces with non-trivial rational homotopy groups.

We study an energy functional on the universal spinor bundle over a closed nn-dimensional spin manifold MM. The critical points of this functional, which is modelled on the total torsion functional of G2G_2-structures in seven dimensions, are pairs of Ricci-flat metrics and real parallel spinor fields provided that $…

2017-12-18abs ↗pdf ↗

Dehn surgery on a knot determines a dual knot in the surgered manifold, the core of the filling torus. We consider duals of knots in S3S^3 that have a lens space surgery. Each dual supports a contact structure. We show that if a universally tight contact structure is supported, then the dual is in the same homology cla…

2014-11-13abs ↗pdf ↗

Geodesic flows on specific manifolds are structurally stable.

problem Stability of geodesic flows on compact manifolds without conjugate points.
method Analyzing the CC^{\infty} compact manifold (M,g)(M,g) with quasi-convex universal covering and divergent geodesic rays.
result Proved the C1C^{1}-stability conjecture for geodesic flows of compact manifolds.

It is well known that spinors on oriented Riemannian manifolds cannot be defined as sections of a vector bundle associated with the frame bundle. For this reason spin and spin^c structures are often introduced. In this paper we prove that spin^c structures have a universal property among all other structures that enabl…

2007-09-15abs ↗pdf ↗

Counterexample found for Stein property of certain solvable Lie groups.

problem Stein property of simply connected unimodular solvable Lie groups with left-invariant complex structures.
method Constructing a solvable Lie group with specific properties.
result A simply connected solvable Lie group with a left-invariant complex structure whose universal cover is not Stein.

Study shows kk-NN classifier is not universally consistent on (0,1)(0,1) but consistent on discrete and specific measure spaces.

problem Consistency of kk-NN classifier under Wasserstein distance on measure spaces.
method Analysis of kk-NN classifier properties under Wasserstein distance, use of σσ-finite metric dimension, geodesic structures of Wasserstein spaces.
result Consistency of kk-NN classifier on specific measure spaces (discrete, Gaussian, wavelet series) but not on (0,1)(0,1).

Deep learning models converge to Gaussian dynamics with mixed structured inputs.

problem Understanding neural network dynamics with complex input distributions.
method Extended hidden manifold model to Gaussian mixtures, analyzed via SGD.
result Learning dynamics with mixed inputs converge to Gaussian behavior.

Proves DCNNs with expansive convolution are strongly universally consistent.

problem Theoretical consistency of deep convolutional neural networks (DCNNs).
method Empirical risk minimization on DCNNs with expansive convolution (with zero-padding).
result DCNNs with expansive convolution are strongly universally consistent.

The Einstein universe is the conformal compactification of Minkowski space. It also arises as the ideal boundary of anti-de Sitter space. The purpose of this article is to develop the synthetic geometry of the Einstein universe in terms of its homogeneous submanifolds and causal structure, with particular emphasis on d…

2007-06-20abs ↗pdf ↗

Develops experimental design for discovering missing physics in bioreactors.

problem Discovering missing physics in incomplete model structures of process systems.
method Combines universal differential equations and symbolic regression with sequential experimental design.
result Successfully recovered true model structure of a bioreactor using machine learning techniques.

Group invariant and equivariant Multilayer Perceptrons (MLP), also known as Equivariant Networks, have achieved remarkable success in learning on a variety of data structures, such as sequences, images, sets, and graphs. Using tools from group theory, this paper proves the universality of a broad class of equivariant M…

2020-02-07abs ↗pdf ↗

NODEs can approximate a wide range of diffeomorphisms with strong guarantees.

problem The approximation power of NODEs under certain conditions.
method Leveraging a structure theorem of the diffeomorphism group.
result NODEs can approximate a large class of diffeomorphisms with a stronger guarantee.

We study the geometry of universal embedding spaces for compact almost complex manifolds of a given dimension. These spaces are complex algebraic analogues of twistor spaces that were introduced by J-P. Demailly and H. Gaussier. Their original goal was the study of a conjecture made by F. Bogomolov, asserting the "tran…

2019-05-15abs ↗pdf ↗

We determine the algebraic structure underlying the geometric complex associated to a link in Bar-Natan's geometric formalism of Khovanov's link homology theory (n=2). We find an isomorphism of complexes which reduces the complex to one in a simpler category. This reduction enables us to specify exactly the amount of i…

2006-03-14abs ↗pdf ↗

We extend a recently proposed 1-nearest-neighbor based multiclass learning algorithm and prove that our modification is universally strongly Bayes-consistent in all metric spaces admitting any such learner, making it an "optimistically universal" Bayes-consistent learner. This is the first learning algorithm known to e…

2019-06-24abs ↗pdf ↗

This paper begins the study of relations between Riemannian geometry and global properties of contact structures on 3-manifolds. In particular we prove an analog of the sphere theorem from Riemannian geometry in the setting of contact geometry. Specifically, if a given three dimensional contact manifold (M,ξ) admits a …

2009-06-18abs ↗pdf ↗

Study of a series of Lorentzian structures on SL(2,R) with SO(1,1) symmetry.

problem Global optimality of extremal trajectories in a series of Lorentzian structures.
method Analysis of a one-parametric series of left-invariant Lorentzian structures on SL(2,R) with SO(1,1) symmetry.
result Properties of the Lorentzian structures deform to those of the sub-Lorentzian structure in a limit case.

The paper explores simple and relatively simple transformation groups and their universal coverings.

problem Understanding the structure of universal coverings of transformation groups.
method Study of relatively simple groups and generalization of Tsuboi's metric space.
result Tsuboi's metric space of Ham~(M,ω)\widetilde{\mathrm{Ham}}(M, ω) is not quasi-isometric to the half line.

Study a simplified model of multiverse structure with synchronized timelines.

problem Understanding the complex structure of the local multiverse with multiple universes.
method Time-amalgamated globally hyperbolic model of multiverse as a collection of parallel universes.
result Elementary particles are transcosmic strings with multiple endpoints on parallel universes.

Universal tester-learner for halfspaces over structured distributions.

problem Learning halfspaces over a wide class of structured distributions.
method Uses a fully polynomial tester-learner based on hypercontractivity and sum-of-squares (SOS) programs.
result Achieves error O(opt)+εO(\mathrm{opt}) + ε on any labeled distribution that the tester accepts.

We explore the complex associated to a link in the geometric formalism of Khovanov's (n=2) link homology theory, determine its exact underlying algebraic structure and find its precise universality properties for link homology functors. We present new methods of extracting all known link homology theories directly from…

2007-06-25abs ↗pdf ↗