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.

168,695 papers · 148 categories

Trend · papers per month

142284425567 · Jun 202019922001200920172026
48 results for sphere sampling

Random column sampling is not guaranteed to yield data sketches that preserve the underlying structures of the data and may not sample sufficiently from less-populated data clusters. Also, adaptive sampling can often provide accurate low rank approximations, yet may fall short of producing descriptive data sketches, es…

2017-05-09abs ↗pdf ↗

Variational Auto-Encoder (VAE) has been widely applied as a fundamental generative model in machine learning. For complex samples like imagery objects or scenes, however, VAE suffers from the dimensional dilemma between reconstruction precision that needs high-dimensional latent codes and probabilistic inference that f…

2019-12-21abs ↗pdf ↗

New summary measures reveal geometric structure in weighted measures on manifolds.

problem Lack of geometric information in standard weight-only summaries.
method Heat-kernel entropy profiles, tracking nonuniformity across scales.
result Geometric effective sample size discounts nearby or duplicate particles.

A new method calculates intrinsic effective sample size for manifold-valued data.

problem Challenges in choosing effective sample size for manifold-valued data.
method Proposes an intrinsic effective sample size based on kernel discrepancy.
result Establishes an exact finite-sample risk interpretation and consistency of the estimator.

Algorithm samples polygons of fixed edge lengths in any dimension.

problem Sampling random closed polygons with fixed edge lengths in any dimension.
method Weighted edge vectors on unit sphere, Möbius transformation, reweighting factors.
result Algorithm samples polygons according to standard probability measures efficiently.

We study the Gibbs sampling algorithm for continuous determinantal point processes. We show that, given a warm start, the Gibbs sampler generates a random sample from a continuous kk-DPP defined on a dd-dimensional domain by only taking poly(k)\text{poly}(k) number of steps. As an application, we design an algorithm to ge…

2018-10-20abs ↗pdf ↗

The Cannon-Thurston map's pushed measures on the circle are singular with respect to sphere measures.

problem Understanding the behavior of geodesics and measures on fibered hyperbolic 3-manifolds.
method Properties of geodesics and measures on the circle and sphere are analyzed to prove singularity.
result Natural measures on the circle become singular with respect to measures on the sphere.

We develop time-uniform confidence spheres for estimating means of random vectors.

problem Sequential mean estimation in high-dimensional spaces.
method Derive time-uniform confidence sphere sequences (CSSs) for various types of random vectors.
result Optimal CSSs for log-concave, sub-Gaussian, and sub-ψψ random vectors.

Random hyperbolic surfaces with punctures converge to the Brownian sphere.

problem Understanding the geometry of random hyperbolic surfaces with punctures.
method Rescaling and encoding via plane trees with continuous labels.
result Rescaled random hyperbolic surfaces converge to the Brownian sphere.

The paper proposes a novel method for optimizing bounded functions using Fourier series and Ricci flow.

problem Optimizing bounded functions using Fourier series and Ricci flow.
method Approximating the initial manifold using Fourier series and center/boundary sampling. Iteratively evolving the manifold using geodesic hyper-spheres and inverse Ricci flow.
result The method allows for the optimization of high curvature regions and achieves potential global optima.

When can a map between manifolds be deformed away from itself? We describe a (normal bordism) obstruction which is often computable and in general much stronger than the classical primary obstruction in cohomology. In particular, it answers our question completely in a large dimension range. As an illustration we give …

2006-06-01abs ↗pdf ↗

Unified high-probability regret bounds for online convex optimisation with randomised gradient estimators.

problem Online convex optimisation with randomised gradient estimators for q\ell_q-Lipschitz losses.
method FTRL with randomised two-point finite-difference gradient estimators based on cone-measure sampling from r\ell_r-spheres.
result Unified high-probability regret bounds for all p,q,r[1,]p,q,r \in [1,\infty].

The paper improves evolutionary computation by optimizing selection rates.

problem Choosing the right selection rate in evolutionary computation.
method The paper proves mathematically that a selection rate of μ/λ leads to better progress rates and provides a theoretical basis for this.
result The theoretical selection rate μ/λ leads to a better progress rate of order O(λ^-1) compared to O(λ^-2/d).

Concerns decompositions of smooth 4-manifolds as the union of two handlebodies, each with handles of index <=2 (``Heegard'' decompositions).Sample result: Two 2-complexes are (up to 2-deformation) dual spines of a Heegard decomposition of the 4-sphere if and only if they satisfy the conclusions of the Alexander-Lefshet…

2000-09-27abs ↗pdf ↗

Bayesian approach approximates probability functions of Gaussian mixtures.

problem Approximating probability functions of non-spherical Gaussian mixtures.
method Bayesian decomposition, spherical radial decomposition, random sampling.
result Established differentiability and integral representation of gradient for probability functions.

The paper provides bounds for the empirical angular measure and applies them to improve statistical learning in extreme regions.

problem Estimating the angular measure in high-dimensional data with different distributions.
method Established bounds for the maximal deviations of the empirical angular measure from the true measure, using rank transformation and analyzing the most extreme observations.
result The bounds provide performance guarantees for statistical learning procedures in extreme regions, such as binary classification and anomaly detection.

Study analyzes learnability of RKHS under L∞ norm for kernel methods.

problem Understand performance of kernel methods and random feature models.
method Relate L∞ learnability to kernel spectrum decay and establish sample complexity bounds.
result Conditions for efficient L∞ learning of RKHS identified.

Kervaire's sphere-link is equivalent to a ribbon sphere-link, simplifying complex 2-complexes.

problem Understanding the structure of 2-complexes and their asphericity.
method Using Kervaire's sphere-link and ribbon sphere-link equivalence, analyzing the compact complement of ribbon disk-links.
result Every connected subcomplex of a contractible finite 2-complex is aspherical.

Given a link map f into a manifold of the form Q = N \times \Bbb R, when can it be deformed to an unlinked position (in some sense, e.g. where its components map to disjoint \Bbb R-levels) ? Using the language of normal bordism theory as well as the path space approach of Hatcher and Quinn we define obstructions \widet…

2004-08-03abs ↗pdf ↗

The study shows how to construct dd-spheres from (d1)(d-1)-spheres and dd-balls without additional vertices.

problem Constructing dd-spheres from (d1)(d-1)-spheres and dd-balls without additional vertices.
method Examining specific types of spheres (flag, stacked, join of spheres) and dd-balls to determine if constructions can be made without extra vertices.
result Affirmative answers to constructing dd-spheres from (d1)(d-1)-spheres and dd-balls without additional vertices for certain types of spheres and dd-balls.

A new distribution addresses scalability and numerical stability issues of the vMF.

problem Scalability and numerical stability issues in sampling from the von Mises-Fisher (vMF) distribution.
method Proposes the Power Spherical distribution, retaining vMF's properties but addressing its drawbacks.
result Demonstrates the stability of Power Spherical distributions and applies it to a variational auto-encoder.

Soliton spheres are immersed 2-spheres in the conformal 4-sphere S^4=HP^1 that allow rational, conformal parametrizations f:CP^1->HP^1 obtained via twistor projection and dualization from rational curves in CP^{2n+1}. Soliton spheres can be characterized as the case of equality in the quaternionic Pluecker estimate. A …

2009-05-13abs ↗pdf ↗

Study on kernel regression risk in high dimensions using Pinsker bound.

problem Kernel regression risk in high-dimensional inner product spaces.
method Investigation of Pinsker bound for kernel regression on sphere Sd\mathbb{S}^{d} with sample size n=αdγ(1+od(1))n = αd^γ(1+o_{d}(1)).
result Exact minimax risk and Pinsker constant identified for kernel regression.

Reduces connectivity problem for genus-4 Heegaard surface in 3-sphere.

problem Connectivity problem in reducing sphere complex for genus-4 Heegaard surface.
method Presented a sufficient condition for a non-separating weak reducing pair to be separated by a reducing sphere.
result Reduced connectivity problem to showing disjointness of representative reducing spheres from a fixed disk.

Paper studies inscribed sphere and lines through centers of Apollonius spheres in n dimensions.

problem Tangency of spheres and lines through their centers.
method Lie sphere geometry and two-step construction of Apollonius spheres.
result Center of inscribed sphere coincides with point PXP_X.

In the 1-parameter family of Berger spheres S^3(a), a > 0 (S^3(1) is the round 3-sphere of radius 1) we classify the stable constant mean curvature spheres, showing that in some Berger spheres (a close to 0) there are unstable constant mean curvature spheres. Also, we classify the orientable compact stable constant mea…

2009-06-08abs ↗pdf ↗

Spherical data is found in many applications. By modeling the discretized sphere as a graph, we can accommodate non-uniformly distributed, partial, and changing samplings. Moreover, graph convolutions are computationally more efficient than spherical convolutions. As equivariance is desired to exploit rotational symmet…

2019-04-08abs ↗pdf ↗

We introduce and study a new class of homotopy spheres called Farrell-Jones spheres. Using Farrell-Jones sphere we construct examples of closed negatively curved manifolds M2nM^{2n}, where n=7n=7 or 88, which are homeomorphic but not diffeomorphic to complex hyperbolic manifolds, thereby giving a partial answer to a que…

2015-10-11abs ↗pdf ↗