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arXiv research

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.

169,341 papers · 148 categories

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87173260346 · Jun 202019922001200920182026
48 results for GH limits

The paper examines sequences of metric spaces converging to compact limits with specific properties.

problem Understanding convergence of metric spaces with compact limits.
method Analyzes sequences of metric spaces with increasing distance functions and uniform bounds, proving convergence under certain conditions.
result Uniform and Gromov-Hausdorff convergence and volume preserving intrinsic flat convergence to compact limits.

Let \gh = \gh_{-k}\oplus \cdots \oplus \gh_{l} (k >0, l \geq 0) be a finite dimensional real graded Lie algebra, with a Euclidian metric \langle \cdot , \cdot \rangle adapted to the gradation. The metric \langle\cdot , \cdot \rangle is called admissible if the codifferentials \partial^{*} : C^{k+1}(\gh_{-}, \gh ) \ra C…

2014-09-30abs ↗pdf ↗

The study examines sequences of Riemannian manifolds with uniform Sobolev bounds and their convergence properties.

problem Analyzing sequences of compact Riemannian manifolds with uniform Sobolev bounds and their convergence.
method Establishing a general trace inequality on Riemannian manifolds and proving convergence properties using Hölder and Intrinsic Flat metrics.
result Sequences of compact Riemannian manifolds with uniform Hölder bounds on their distance functions have subsequences converging in the Gromov--Hausdorff sense.

Defines new metrics for Lorentzian spaces and their convergence.

problem Defining metrics for Lorentzian spaces and their convergence.
method Abstract approach to Lorentzian Gromov-Hausdorff distance and convergence, defining bounded Lorentzian-metric spaces, and proving stability under GH limits.
result GH limits of Lorentzian-metric spaces are isometric and homeomorphic.

The paper constructs manifolds with infinite holes from a given manifold.

problem Creating manifolds with infinite holes from a given manifold.
method Constructing a sequence of (n+2)(n+2)-dimensional manifolds (Mi,gi)(M_{i} ,g_i ) with mRicgi>λ{ m Ric}_{g_i} > λ that approximate the original manifold (X,h)(X,h) and have an infinite number of connected components.
result The constructed manifolds (Xε)(X_ε) have dense boundary with an infinite number of connected components and no open subset topologically a manifold.

The abstract discusses a new type of space and its properties.

problem The abstract tackles the concept of non-Hilbertian (Lorentzian) length spaces.
method The abstract introduces a new type of space and analyzes its properties.
result The abstract finds that normed spaces without inner products have no sectional curvature bounds.

Survey of nonnegative scalar curvature sequences and their limits.

problem Understanding sequences of manifolds with nonnegative scalar curvature.
method Analyzing sequences of manifolds with nonnegative scalar curvature and proving convergence.
result Proved the GH and SWIF convergence of an extreme example.

We consider (flat) Cauchy-complete GH spacetimes, i.e., globally hyperbolic flat lorentzian manifolds admitting some Cauchy hypersurface on which the ambient lorentzian metric restricts as a complete riemannian metric. We define a family of such spacetimes - model spacetimes - including four subfamilies: translation sp…

2004-02-16abs ↗pdf ↗

Study shows no new Euclidean factors can appear in the limit of CAT(0) spaces.

problem Stability of Euclidean factors in CAT(0) spaces under convergence.
method GH-convergence of CAT(0) spaces with uniformly cocompact discrete groups of isometries.
result Dimension of the maximal Euclidean factor is the same for large jj.

GH-PID uses guided harmonic paths for efficient SOT with interpretable diagnostics.

problem Efficiently solving Stochastic Optimal Transport with hard terminal distributions and soft costs.
method Guided Harmonic Path-Integral Diffusion (GH-PID) framework with low-dimensional guidance.
result GH-PID generates geometry-aware, cost-reducing trajectories that match terminal distributions.

This paper extends FP's method to complex hyperbolic branched covers to find Einstein metrics.

problem Finding Einstein metrics on non-locally symmetric manifolds.
method Generalized FP's construction to complex hyperbolic branched covers.
result Yields a negatively curved Einstein metric that asymptotically approaches GH's metric.

The paper improves estimates on singular sets in manifolds with integral curvature bounds.

problem Estimating the singular set of manifolds with integral curvature bounds.
method Using Gromov-Hausdorff limits and Cheeger-Naber methods.
result Improved Minkowski dimension estimate for singular sets.

Consider a limit space (Mα,gα,pα)GH(Y,dY,p)(M_α,g_α,p_α)\stackrel{GH}{\rightarrow} (Y,d_Y,p), where the MαnM_α^n have a lower Ricci curvature bound and are volume noncollapsed. The tangent cones of YY at a point pYp\in Y are known to be metric cones C(X)C(X), however they need not be unique. Let $\barΩ_{Y,p}\subseteq\cM_{GH}$ be the close…

2011-08-16abs ↗pdf ↗

Study on null hypersurfaces in complex contact manifolds.

problem Characterizing null hypersurfaces in indefinite complex contact manifolds.
method Proved classification results for various null hypersurfaces and characterized the ambient space.
result The ambient complex contact manifold must have constant GHGH-sectional curvature of 3-3 for certain null hypersurfaces.

A Riemannian or Finsler metric on a compact manifold M gives rise to a length function on the free loop space ΛM, whose critical points are the closed geodesics in the given metric. If X is a homology class on ΛM, the minimax critical level cr(X) is a critical value. Let M be a sphere of dimension >2, and fix a metric …

2011-05-04abs ↗pdf ↗

In this paper, we are concerned with the regularity of noncollapsed Riemannian manifolds (Mn,g)(M^n,g) with bounded Ricci curvature, as well as their Gromov-Hausdorff limit spaces (Mjn,dj)dGH(X,d)(M^n_j,d_j)\stackrel{d_{GH}}{\longrightarrow} (X,d), where djd_j denotes the Riemannian distance. Our main result is a solution to the codimen…

2014-06-25abs ↗pdf ↗

Consider a hyperbolic group G and a quasiconvex subgroup H of infinite index. We construct a set-theoretic section s of the quotient map (of sets) from G to G/H such that s(G/H) is a net in G; that is, any element of G is a bounded distance from s(G/H). This section arises naturally as a set of points minimizing word-l…

2006-08-09abs ↗pdf ↗

4-manifolds with Ricci curvature bounds can be approximated by non-manifold spaces.

problem Existence of manifold structure in 4-manifolds with Ricci curvature bounds.
method Constructing 4-rectifiable metric spaces that are limits of manifolds with Ricci curvature bounds.
result 4-manifolds can be approximated by spaces that are nowhere topologically manifolds.

Paper introduces MSP Network for harmonizing images from different scanners.

problem Improving predictive performance and learning efficiency in data harmonization.
method Multi-Stage Prediction (MSP) Network integrating neural networks of different architectures.
result MSP Network shows 20% improvement in patch-based mean-squared error over state-of-the-art methods.

We study here limit spaces (Mα,gα,pα)GH(Y,dY,p)(M_α,g_α,p_α)\stackrel{GH}{\rightarrow} (Y,d_Y,p), where the MαM_α have a lower Ricci curvature bound and are volume noncollapsed. Such limits YY may be quite singular, however it is known that there is a subset of full measure $\cR(Y)\subseteq Y$, called {\it regular} points, along with c…

2011-11-09abs ↗pdf ↗

Enhanced probabilistic sampling on manifolds using Double Diffusion Maps and Geometric Harmonics.

problem Overfitting and loss of generalization in PLoM when N is small and dimensionality approaches N.
method Extending PLoM with Double Diffusion Maps and Geometric Harmonics to handle small N and high-dimensional data.
result Effective and robust method for generating statistically consistent realizations from limited data.

Let MM be an nn-dimensional complete Riemannian manifold with Ricci curvature n1\ge n-1. In \cite{colding1, colding2}, Tobias Colding, by developing some new techniques, proved that the following three condtions: 1) dGH(M,Sn)0d_{GH}(M, S^n)\to 0; 2) the volume of MM Vol(M)Vol(Sn){\text{Vol}}(M)\to{\text{Vol}}(S^n); 3) the radius of $M…

2014-01-21abs ↗pdf ↗

Rectifies singular sets in noncollapsed spaces with Ricci curvature bounds.

problem Understanding the structure of singular sets in noncollapsed spaces with Ricci curvature bounds.
method Analysis of Gromov-Hausdorff limit spaces, filtration of singular sets, and use of cone-splitting and geometric transformation theorems.
result The singular set SkS^k is kk-rectifiable, and every tangent cone at kk-dimensional points is kk-symmetric.

In this paper, we quantitatively investigate the statistical properties of a statistical ensemble of stock prices. We selected 1200 stocks traded on the Tokyo Stock Exchange, and formed a statistical ensemble of daily stock prices for each trading day in the 3-year period from January 4, 1999 to December 28, 2001, corr…

2006-03-17abs ↗pdf ↗

The article introduces a new convergence concept for Lorentzian spaces and applies it to generalized cones.

problem Stability of curvature bounds in generalized Lorentzian cones.
method Introduces \ell-convergence for Lorentzian pre-length spaces, applies it to generalized cones, and proves stability of curvature bounds.
result Sharp timelike curvature and curvature-dimension bounds for generalized cones are established.

Study proposes a new portfolio selection method using non-Gaussian models and Esscher transform.

problem Portfolio selection with complex stock return structures and skewness, kurtosis.
method Multivariate non-Gaussian models (NTS and GH), Esscher transform for risk-neutral measure, simultaneous calibration of univariate log-returns and volatility.
result Demonstrated the effectiveness of the proposed models in fitting and selecting portfolios.

A para-Kähler manifold can be defined as a pseudo-Riemannian manifold (M,g)(M,g) with a parallel skew-symmetric para-complex structures KK, i.e. a parallel field of skew-symmetric endomorphisms with K2=Id K^2 = \mathrm{Id} or, equivalently, as a symplectic manifold (M,ω)(M,ω) with a bi-Lagrangian structure L±L^\pm, i.e. two c…

2008-06-13abs ↗pdf ↗

The paper establishes a new link between isometries and scaling nonvanishing property in manifolds with Ricci curvature.

problem Lack of links between large-scale and small-scale geometry in manifolds with Ricci curvature.
method Investigates isometric actions with scaling nonvanishing property and their implications on the structure of manifolds.
result Establishes a dimension monotonicity on the limit group associated with rescaling sequences of universal covers.

This paper studies the relationship between fundamental groups of manifolds and their effective regular sets.

problem Understanding the relationship between fundamental groups of manifolds and their effective regular sets.
method Constructing surjective homomorphisms between fundamental groups and effective regular sets.
result Natural homomorphisms φiφ_i and ψiψ_i are constructed, with their composition equal to the induced homomorphism by inclusion.

In this paper, we quantitatively investigate the properties of a statistical ensemble of stock prices. We focus attention on the relative price defined as X(t)=S(t)/S(0) X(t) = S(t)/S(0) , where S(0) S(0) is the initial price. We selected approximately 3200 stocks traded on the Japanese Stock Exchange and formed a statistical ensem…

2005-10-07abs ↗pdf ↗

Paper proposes new Bayesian neural network models for efficient learning.

problem Efficient learning and model compression in deep neural networks.
method Proposes Spike-and-Slab Group Lasso (SS-GL) and Spike-and-Slab Group Horseshoe (SS-GHS) priors for structured sparsity in Bayesian neural networks.
result Establishes competitive performance in prediction accuracy, model compression, and inference latency compared to baseline models.

Proves cosets of certain subgroups in hyperbolic 3-manifold groups are conjugacy distinguished.

problem Characterizing conjugacy distinguished cosets in hyperbolic 3-manifold groups.
method Analyzes conjugacy distinguished cosets of specific subgroups in hyperbolic 3-manifold groups.
result Cosets of loxodromic subgroups are conjugacy distinguished from maximal parabolic subgroups.

We consider maximum solution g(t)g(t), t[0,+)t\in [0, +\infty), to the normalized Ricci flow. Among other things, we prove that, if (M,ω)(M, ω) is a smooth compact symplectic 4-manifold such that b2+(M)>1b_2^+(M)>1 and let g(t),t[0,)g(t),t\in[0,\infty), be a solution to (1.3) on MM whose Ricci curvature satisfies that $|\text{Ric}(g(t))|\l…

2007-04-05abs ↗pdf ↗

The paper proves rigidity theorems for Poincaré-Einstein manifolds with specific conformal properties.

problem Rigidity of Poincaré-Einstein manifolds with standard sphere conformal infinity.
method Analyzes two types of Yamabe constants and derives inequalities to prove rigidity.
result Equality in inequalities between Yamabe constants implies isometry to standard hyperbolic space.