Research
On-device research index

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.

168,657 papers · 148 categories

Trend · papers per month

208417625833 · Jun 202019922001200920172026
48 results for sphere optimization

New optimal surfaces found in Heisenberg group defy Euclidean sphere optimality.

problem Optimizing mean curvature in Heisenberg group sub-Riemannian setting.
method Developed variational theory, established first and second variation formulas, introduced new critical surfaces.
result Identified and characterized a new family of rotationally invariant critical surfaces, the Pansu-Minkowski spheres.

Sharp bounds found on shortest geodesic on punctured spheres.

problem Finding the shortest closed geodesic on punctured spheres.
method Sharp curvature-free upper bounds expressed in terms of area, extremal metrics described.
result Optimal bounds for spheres with up to four ends, extended to larger numbers of punctures.

This study shows the moment-SOS hierarchy converges in polynomial optimization over product of spheres.

problem Minimizing multihomogeneous polynomials over product of spheres.
method Moment-SOS hierarchy, local optimality conditions, differential geometry, Morse theory.
result The moment-SOS hierarchy has finite convergence for generic multihomogeneous objective functions.

Optimal controls for conformal Laplacian obstacle problems on spheres and manifolds.

problem Optimal control of conformal metrics with constant scalar curvature.
method Analysis of optimal control problem on Riemannian manifolds with positive Yamabe invariant.
result Existence of smooth optimal controls inducing metrics with constant scalar curvature.

In this paper the regularity of optimal transportation potentials defined on round spheres is investigated. Specifically, this research generalises the calculations done by Loeper, where he showed that the strong (A3) condition of Trudinger and Wang is satisfied on the round sphere, when the cost-function is the geodes…

2009-01-18abs ↗pdf ↗

The paper characterizes Whitney and contact Whitney spheres in complex and Sasakian space forms.

problem Characterizing spheres in complex and Sasakian space forms.
method Establishing optimal integral inequalities involving Ricci curvature and second fundamental form norms.
result New characterizations of Whitney and contact Whitney spheres in complex and Sasakian space forms.

Using a ramified cover of the two-sphere by the torus, we prove a local optimal inequality between the diastole and the area on the two-sphere near a singular metric. This singular metric, made of two equilateral triangles glued along their boundary, has been conjectured by E. Calabi to achieve the best ratio area over…

2008-11-03abs ↗pdf ↗

In this paper, we study the rigidity theorem of closed minimally immersed Legendrian submanifolds in the unit sphere. Utilizing the maximum principle, we obtain a new characterization of the Calabi torus in the unit sphere which is the minimal Calabi product Legendrian immersion of a point and the totally geodesic Lege…

2019-11-19abs ↗pdf ↗

Whitening, or sphering, is a common preprocessing step in statistical analysis to transform random variables to orthogonality. However, due to rotational freedom there are infinitely many possible whitening procedures. Consequently, there is a diverse range of sphering methods in use, for example based on principal com…

2015-12-02abs ↗pdf ↗

The study connects spheres in specific surface curve graphs, proving connectivity and classifying components.

problem Proving connectivity and classifying components of spheres in curve graphs of low and medium complexity surfaces.
method Analyzing specific surfaces Σ2,0,Σ1,3,Σ0,6Σ_{2,0}, Σ_{1,3}, Σ_{0,6} and Σ0,5,Σ1,2Σ_{0,5}, Σ_{1,2}, proving connectivity and classifying components.
result Spheres of any radius are connected in Σ2,0,Σ1,3,Σ0,6Σ_{2,0}, Σ_{1,3}, Σ_{0,6}, and the union of two consecutive spheres is connected in Σ0,5Σ_{0,5} and Σ1,2Σ_{1,2}.

Existence of harmonic maps from higher-dimensional manifolds to spheres proven.

problem Proving existence of nonconstant harmonic maps from arbitrary manifolds to spheres.
method Using optimal regularity and eigenvalue optimization on manifolds.
result First general existence result for harmonic maps from higher-dimensional manifolds to a large class of positively curved targets.

Optimizes sharp curvature inequality on spheres, proving near-minimizers are close to standard metric.

problem Optimizing total σ2σ_2-curvature on spheres with positive scalar curvature.
method Analyzes metrics conformal to the standard sphere, uses Sobolev norms to measure closeness.
result Near-minimizers of total σ2σ_2-curvature are almost the standard metric (up to Möbius transformations).

Study rigidity of minimal Legendrian submanifolds in spheres via eigenvalues.

problem Rigidity of minimal Legendrian submanifolds in unit Euclidean spheres.
method Using Lu's inequality and eigenvalues of fundamental matrices to establish pinching theorems.
result Optimal pinching theorem and rigidity theorem for submanifolds of all dimensions.

Three training regimes found for scale-invariant neural networks on the sphere.

problem Training scale-invariant neural networks on the sphere with varying effective learning rate.
method Investigated three regimes of training: convergence, chaotic equilibrium, and divergence.
result Discovered three distinct training regimes with unique characteristics.

Bayesian framework for sphere regression using Gaussian fields.

problem Nonparametric regression on the sphere with Gaussian priors.
method Isotropic Gaussian field priors, harmonic structure, exact posterior distributions, optimal spectral truncation, posterior contraction rates.
result Sharp posterior contraction rates for Gaussian priors with polynomially decaying angular power spectra.

Improved persistence spheres map measures to functions, stable under partial transport.

problem Representing and comparing measures in topological machine learning.
method Persistence spheres map measures to continuous functions on the sphere, stable under 1-Wasserstein partial transport.
result Persistence spheres provide a stable, parameter-free representation of measures, improving upon existing methods.

In this note we provide natural optimal geometric conditions for a Riemannian manifold suitably covered by two open metric balls to be homeomorphic to a sphere. This can be viewed as a geometric analogue of Brown's theorem in topology stating that a closed manifold covered by two topological balls is a sphere.

2016-10-26abs ↗pdf ↗

A new differentiable sphere theorem is obtained from the view of submanifold geometry. An important scalar is defined by the scalar curvature and the mean curvature of an oriented complete submanifold MnM^n in a space form Fn+p(c)F^{n+p}(c) with c0c\ge0. Making use of the Hamilton-Brendle-Schoen convergence result for Ricci…

2010-05-14abs ↗pdf ↗

For decades, the sphere eversion has been a classic subject for mathematical visualization. The 1998 video "The Optiverse" shows geometrically optimal eversions created by minimizing elastic bending energy. We contrast these minimax eversions with earlier ones, including those by Morin, Phillips, Max, and Thurston. The…

1999-05-04abs ↗pdf ↗

Sphere theorems proved for manifolds with specific curvature conditions.

problem Sphere theorems for Riemannian manifolds with curvature operator constraints.
method Investigation of eigenvalues and curvature operator conditions.
result Proved sphere theorems in dimensions three and four, homological sphere theorem in higher dimensions.

This article addresses regularity of optimal transport maps for cost="squared distance" on Riemannian manifolds that are products of arbitrarily many round spheres with arbitrary sizes and dimensions. Such manifolds are known to be non-negatively cross-curved [KM2]. Under boundedness and non-vanishing assumptions on th…

2010-06-10abs ↗pdf ↗

Proves existence of maximizers for eigenvalue optimization on manifolds.

problem Eigenvalue optimization on Riemannian manifolds of dimension m3m \geq 3.
method Use of topological tensor products to analyze eigenvalue functionals.
result Absolutely continuous maximizers are induced by pp-harmonic maps into spheres.

This paper embeds surfaces in 3D spheres and balls with minimal area.

problem Embed surfaces with boundary in B3\mathbb{B}^3 as minimal surfaces.
method Optimizing Laplace and Steklov eigenvalues with symmetry groups.
result Proves existence of minimal surfaces in B3\mathbb{B}^3 with area below 2π2\pi.

Optimizes energy of mappings from complex projective spaces.

problem Finding energy-minimizing mappings between complex projective spaces and Riemannian manifolds.
method Establishes optimal lower bounds for energy functionals and characterizes optimal mappings.
result Optimal lower bounds for energy functionals are characterized for mappings from real and complex projective spaces.

The paper optimizes Dirac eigenvalues on surfaces and connects them to harmonic maps into complex projective spaces.

problem Optimizing the kk-th positive Dirac eigenvalue on surfaces with fixed area and conformal class.
method Connecting the problem to the maximization of Laplacian eigenvalues and using critical metrics for Dirac eigenvalues and harmonic maps into complex projective spaces.
result The first nonzero Dirac eigenvalue on a torus is minimized by the flat metric.

The study characterizes homology 4-manifolds with g25g_2\leq 5 combinatorially.

problem Characterizing homology 4-manifolds with specific g2g_2 values.
method Combinatorial approach using various operations on triangulated 4-spheres.
result Homology 4-manifolds with g25g_2\leq 5 are triangulated spheres and can be derived from 4-spheres with g22g_2\leq 2.

In recent years, spectral clustering has become a standard method for data analysis used in a broad range of applications. In this paper we propose a new class of algorithms for multiway spectral clustering based on optimization of a certain "contrast function" over the unit sphere. These algorithms, partly inspired by…

2014-03-04abs ↗pdf ↗