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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.

169,291 papers · 148 categories

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25.0%50.0%75.0%100.0% · Feb 199419922001200920182026
48 results for Riemannian case

The paper derives inequalities for Riemannian maps and submersions involving quaternionic space forms.

problem Establishing optimal inequalities for Riemannian maps and submersions involving quaternionic space forms.
method Deriving Casorati inequalities for Riemannian maps and submersions involving quaternionic space forms.
result Geometric characterizations of equality cases for Riemannian maps and submersions involving quaternionic space forms.

There is a well developed theory of weakly symmetric Riemannian manifolds. Here it is shown that several results in the Riemannian case are also valid for weakly symmetric pseudo-Riemannian manifolds, but some require additional hypotheses. The topics discussed are homogeneity, geodesic completeness, the geodesic orbit…

2011-07-22abs ↗pdf ↗

Study proves estimate for Hessian quotient equations on 2D Riemannian manifolds.

problem Problems posed by Delanoë and Urbas related to Hessian quotient equations.
method Maximum principle argument and new test function introduced to prove estimate.
result Unobstructed second order a priori estimate for real Hessian quotient equation in 2D.

This paper provides a study of algebraic Ricci solitons in the pseudo-Riemannian case. In the Riemannian case, all nontrivial homogeneous algebraic Ricci solitons are expanding algebraic Ricci solitons. In this paper, we obtain a steady algebraic Ricci soliton and a shrinking algebraic Ricci soliton in the Lorentzian s…

2011-12-02abs ↗pdf ↗

In the present paper we consider generic Sub-Riemannian structures on the co-rank 1 non-holonomic vector distributions and introduce the associated canonical volume and ''horizontal'' area forms. As in the classical case, the Sub-Riemannian minimal surfaces can be defined as the critical points of the '`horizontal'' ar…

2006-04-23abs ↗pdf ↗

The paper proves non-existence results for λ-biharmonic submersions from curved manifolds.

problem Proving non-existence of λ-biharmonic submersions from curved manifolds.
method Analyzing λ-biharmonic Riemannian submersions from (n + 1)-dimensional Riemannian manifolds with constant sectional curvature c.
result Critical value λ= 2(n - 1)c plays a decisive role in the non-existence of λ-biharmonic submersions.

Lorentzian versions of classical Riemannian volume comparison theorems by Gunther, Bishop and Bishop-Gromov, are stated for suitable natural subsets of general semi-Riemannian manifolds. The problem is more subtle in the Bishop-Gromov case, which is extensively discussed. For the general semi-Riemannian case, a local v…

1998-11-27abs ↗pdf ↗

The paper derives Chen-Ricci inequalities for Riemannian submersions and maps.

problem Chen-Ricci inequalities for Riemannian submersions and maps.
method General forms of Chen-Ricci inequalities for Riemannian submersions and maps are derived, involving curvatures of subspaces.
result New, easy, and elegant techniques for Chen-Ricci inequalities are established.

Study optimal transport in 4D sub-Riemannian spaces with many singular geodesics.

problem Existence and uniqueness of optimal transport maps in sub-Riemannian structures.
method Analysis of Monge optimal transport problem in sub-Riemannian manifolds.
result Extension of previous results to sub-Riemannian structures of rank two in 4D.

The paper studies limits of sub-Riemannian Heisenberg manifolds and proves convergence under certain conditions.

problem The study of limits of sub-Riemannian Heisenberg manifolds and their properties.
method Analysis of Gromov-Hausdorff limits with upper and lower bounds on diameter and Popp's measure.
result The non-collapsed limits of sub-Riemannian Heisenberg manifolds converge to a compact Heisenberg manifold.

Study on volume of tubes and concentration in Riemannian geometry.

problem Understanding concentration loci in Riemannian manifolds and their relation to tube volumes.
method Provided a general formula for tube volumes, specialized to totally geodesic submanifolds, and investigated concentration loci.
result Explicitly proved concentration for codimension one cases and explored characterizations in Wasserstein and Box distances.

Study on sub-Riemannian manifolds, focusing on conjugate points and caustic stability.

problem Analyzing sub-Riemannian manifolds and their conjugate points.
method Computed sub-Riemannian Hamiltonian flow, approximated conjugate locus, introduced geometric invariant.
result Contact distributions exhibit unique behavior, different from 3D case.

The paper establishes new Casorati inequalities for various Riemannian maps and submersions.

problem Developing new inequalities for Riemannian maps and submersions.
method Using general forms of Casorati inequalities, the paper derives inequalities for specific Riemannian spaces.
result The paper provides new Casorati inequalities for Riemannian maps and submersions.

Study spectral properties of sub-Riemannian Laplacians, proving quantum ergodicity and heat kernel asymptotics.

problem Spectral properties of sub-Riemannian Laplacians.
method Quantum ergodicity results, small-time asymptotics of sub-Riemannian heat kernels, Weyl law.
result Weyl law and spectral concentration on Lie brackets of length r-1.

We study barycenters in the space of probability measures on a Riemannian manifold, equipped with the Wasserstein metric. Under reasonable assumptions, we establish absolute continuity of the barycenter of general measures ΩP(P(M))Ω\in P(P(M)) on Wasserstein space, extending on one hand, results in the Euclidean case (for ba…

2014-12-24abs ↗pdf ↗

Sharp Hardy inequalities on Riemannian submanifolds with non-negative curvature.

problem Establishing Hardy inequalities for submanifolds in Riemannian geometry.
method Analyzing distance functions and using Riemannian submanifolds with non-negative curvature.
result Sharp weighted Hardy inequalities valid for compact and non-compact submanifolds, even in compact ambient manifolds.

New pseudo-Riemannian nilmanifolds classified from earlier work.

problem Classifying weakly symmetric pseudo-Riemannian nilmanifolds.
method From earlier classification of weakly symmetric pseudo-Riemannian manifolds, extended to nilmanifolds with compact HH and nilpotent NN.
result A plethora of new isometric pseudo-Riemannian nilmanifolds identified.

Investigates locally symmetric polynomial metrics in Riemannian and Finslerian surfaces.

problem Analyzing locally symmetric polynomial metrics in Riemannian and Finslerian surfaces.
method Examines Riemannian and Finslerian surfaces, providing necessary and sufficient conditions for locally symmetric fourth root metrics in 2D and more complex conditions for higher dimensions.
result Formulates conditions for positive definiteness of locally symmetric polynomial metrics in Finslerian surfaces and provides explicit examples.

Study geodesic orbit property on pseudo-Riemannian H-type nilmanifolds.

problem Characterize geodesic orbit property for pseudo-Riemannian H-type Lie groups.
method Extend results from Riemannian to pseudo-Riemannian H-type Lie groups, focusing on minimal admissible Clifford modules.
result Complete characterization of geodesic orbit property for pseudo-Riemannian H-type Lie groups.

The paper tackles scalar curvature on manifolds conformal to tori, proving stability under certain conditions.

problem Proving the geometric stability conjecture for scalar curvature on manifolds conformal to tori.
method Reduction via the Yamabe problem and handling sequences of manifolds conformal to flat tori or constant negative scalar curvature.
result Proves the geometric stability conjecture for certain sequences of manifolds conformal to flat tori.

Two new methods solve nonsmooth optimization on Riemannian Stiefel manifold.

problem Optimization over nonsmooth, non-differentiable functions on Riemannian manifolds.
method R-ProxSGD and R-ProxSPB, generalizing proximal SGD and SpiderBoost.
result R-ProxSPB finds ε-stationary points with IFO complexity of Ø(ε^(-3)) in online and Ø(n + √nε^(-2)) in finite-sum cases.

The paper derives inequalities for Riemannian submersions and applies them to specific space forms.

problem Deriving inequalities for Riemannian submersions.
method Introducing and deriving inequalities for vertical, horizontal, and mixed distributions of Riemannian submersions.
result Established relationships between intrinsic and extrinsic invariants of Riemannian submersions.

Riemannian algorithms converge at Euclidean rates for geodesically convex-concave problems.

problem Min-max optimization on Riemannian manifolds.
method RCEG method and RGDA for geodesically strongly-convex-concave problems.
result RCEG achieves linear convergence rate in geodesically strongly-convex-concave cases.

This paper classifies 4D spin manifolds with skew Killing spinors.

problem Classifying 4D Riemannian spin manifolds with skew Killing spinors.
method Analyzing skew Killing spinors with skew-symmetric endomorphisms A, considering both degenerate and non-degenerate cases.
result In the degenerate case, the manifold is locally isometric to R x N with N having a skew Killing spinor.

Classifies all flat Riemannian metrics on the plane, including complete and incomplete cases.

problem Classifying all flat Riemannian metrics on the plane.
method Examined conformal metrics of the form \( e^{2\varphi}g_0 \) where \( \varphi \) is a harmonic function.
result All flat Riemannian metrics on the plane, including complete and incomplete cases, arise from Riemann surfaces.

Study of intrinsic sub-Laplacian for hypersurfaces in contact sub-Riemannian manifolds.

problem Characterizing the intrinsic sub-Laplacian for hypersurfaces in contact sub-Riemannian manifolds.
method Construction and analysis of the intrinsic sub-Laplacian using Riemannian approximations and stochastic processes.
result The intrinsic sub-Laplacian is stochastically complete, ensuring the process does not hit characteristic points.

By making use of the classification of real simple Lie algebra, we get the maximum of the squared length of restricted roots case by case, thus we get the upper bounds of sectional curvature for irreducible Riemannian symmetric spaces of compact type. As an application, we verify Sampson's conjecture in all cases for i…

2005-05-29abs ↗pdf ↗

We show that a simply connected Riemannian homogeneous space M which admits a totally geodesic hypersurface F is isometric to either (a) the Riemannian product of a space of constant curvature and a homogeneous space, or (b) the warped product of the Euclidean space and a homogeneous space, or (c) the twisted product o…

2012-10-18abs ↗pdf ↗

The paper studies symmetry reduction and optimal control on Riemannian manifolds.

problem Symmetry reduction and optimal control on Riemannian manifolds.
method Derivation of reduced equations of motion for variational problems on Lie groups and Riemannian homogeneous spaces.
result Derivation of geodesic equations and reduced equations of motion for various applications.