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.

168,742 papers · 148 categories

Trend · papers per month

3774110147 · Jun 202019922001200920172026
48 results for Spherical Normalization

In this article, we investigate Bertrand curves corresponding to the spherical images of the tangent, binormal, principal normal and Darboux indicatrices of a space curve in Euclidean 3-space. As a result, in case of a space curve is a general helix, we show that the curves corresponding to the spherical images of its …

2010-10-18abs ↗pdf ↗

Derives TAP approximation for Bayesian linear regression.

problem Log-normalizing constant of posterior distribution in high-dimensional linear regression.
method Variational representation and Thouless-Anderson-Palmer approximation.
result Proves TAP approximation for spherical prior in proportional asymptotic regime.

Two subset germs of Euclidean spaces are called blow-spherically equivalent, if their spherical modifications are homeomorphic and the homeomorphism induces homeomorphic tangent links. Blow-spherical equivalence is stronger than the topological equivalence but weaker than the Lipschitz equivalence. We introduce the thi…

2015-05-27abs ↗pdf ↗

The paper classifies equivariant test configurations for spherical varieties.

problem Classifying equivariant test configurations for spherical varieties.
method Combinatorial data classification of equivariant normal R-test configurations.
result Finiteness theorem of central fibers of G-equivariant special R-test configurations.

This paper uses a geometric approach to understand how normalization layers affect neural network optimization.

problem Understanding the effect of normalization layers on optimization in neural networks.
method Introduces a spherical framework to study optimization dynamics of neural networks with normalization layers from a geometric perspective.
result Derives the first effective learning rate expression of Adam and shows that SGD with NLs is equivalent to a constrained variant of Adam.

In the present study we consider the generalized rotational surfaces in Euclidean spaces. Firstly, we consider generalized spherical curves in Euclidean (n+1)(n+1)-space En+1\mathbb{E}^{n+1}. Further, we introduce some kind of generalized spherical surfaces in Euclidean spaces E3\mathbb{E}^{3} and % \mathbb{E}^{4} respect…

2016-05-02abs ↗pdf ↗

In this paper, we study the spherical indicatrices of W-direction curves in three dimensional Euclidean space which were defined by using the unit Darboux vector field W of a Frenet curve, in [11]. We obtain the Frenet apparatus of these spherical indicatrix curves and the characterizations of being general helix and s…

2015-06-12abs ↗pdf ↗

The paper characterizes curves in pseudo-Galilean 4-space.

problem Characterizing curves in the pseudo-Galilean 4-space G14G_{1}^{4}.
method Investigation and characterisation of admissible curves in terms of curvature functions.
result Necessary and sufficient conditions for admissible rectifying curves in G14G_{1}^{4}.

It is known that the space of convex polygons in the Euclidean plane with fixed normals, up to homotheties and translations, endowed with the area form, is isometric to a hyperbolic polyhedron. In this note we show a class of convex polygons in the Lorentzian plane such that their moduli space, if the normals are fixed…

2011-11-15abs ↗pdf ↗

The paper classifies 3D spherical Sasakian manifolds using geometric and algebraic methods.

problem Classifying 3D spherical Sasakian manifolds with specific properties.
method Establishing correspondence between different sets of parameters and geometrically describing the moduli space.
result Determination of Sasakian automorphism groups and detection of homogeneous Sasakian manifolds.

It is known that every ribbon category with unimodality allows symmetrized 6j6j-symbols with full tetrahedral symmetries while a spherical category does not in general. We give an explicit counterexample for this, namely the category E\mathcal{E}. We define the mirror conjugate symmetry of 6j6j-symbols instead and sho…

2009-07-13abs ↗pdf ↗

We prove that the exponential growth rate of the regular language of penetration sequences is smaller than the growth rate of the regular language of normal form words, if the acceptor of the regular language of normal form words is strongly connected. Moreover, we show that the latter property is satisfied for all irr…

2014-03-11abs ↗pdf ↗

Study reveals dynamics of neural networks with normalization, weight decay, and SGD.

problem Understanding the equilibrium condition in Spherical Motion Dynamics (SMD).
method Investigates SMD by exploring the cause of equilibrium condition, introducing assumptions, proposing angular update, and verifying theoretical results.
result Proves weight norm and angular update can converge at linear rate under given assumptions.

New method models intensity functions on spheres using normalizing flows.

problem Modeling non-homogeneous Poisson process intensity functions on the sphere.
method Flexible bijective map using normalizing flows to transform intensity functions.
result Normalizing flows provide a flexible way to model intensity functions on spheres.

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.

For a Riemannian manifold Mn+1M^{n+1} and a compact domain ΩMn+1Ω\subset M^{n+1} bounded by a hypersurface Ω\partial Ω with normal curvature bounded below, estimates are obtained in terms of the distance from OO to Ω\partial Ω for the angle between the geodesic line joining a fixed interior point OO in ΩΩ to a point on…

2012-12-28abs ↗pdf ↗

A curve is rectifying if it lies on a moving hyperplane orthogonal to its curvature vector. In this work, we extend the main result of [Chen 2017, Tamkang J. Math. 48, 209] to any space dimension: we prove that rectifying curves are geodesics on hypercones. We later use this association to characterize rectifying curve…

2019-08-07abs ↗pdf ↗

The spherical Radon transform on the unit sphere can be regarded as a member of the analytic family of suitably normalized generalized cosine transforms. We derive new formulas for these transforms and apply them to study classes of intersections bodies in convex geometry.

2006-02-24abs ↗pdf ↗

Study describes how conformal metrics behave as Q-curvature changes, forming spherical bubbles.

problem Understanding the asymptotic behavior of conformal metrics with null Q-curvature.
method Analyzes the GJMS operator and uses higher order Bol's inequality to describe the metrics' behavior.
result Normalized conformal metrics form exactly one spherical bubble as λ approaches zero.

We prove an estimate for spherical functions φλ(a)\varphi_λ(a) on SL(3,R)\mathrm{SL}(3,\mathbb{R}), establishing uniform decay in the spectral parameter λλ when the group parameter aa is restricted to a compact subset of the abelian subgroup A\mathrm{A}. In the case of SL(3,R)\mathrm{SL}(3,\mathbb{R}), it improves a result by J.…

2019-10-02abs ↗pdf ↗

We study two-dimensional Finsler metrics of constant flag curvature and show that such Finsler metrics that admit a Killing field can be written in a normal form that depends on two arbitrary functions of one variable. Furthermore, we find an approach to calculate these functions for spherically symmetric Finsler surfa…

2017-02-22abs ↗pdf ↗

Kähler-Einstein metrics found on special types of symmetric varieties.

problem Finding Kähler-Einstein metrics on smooth Fano symmetric varieties with specific properties.
method Used a combinatorial criterion for K-stability of Fano spherical varieties and computed algebraic moment polytopes and barycenters.
result Proved all smooth Fano symmetric varieties with Picard number one admit Kähler-Einstein metrics.

In discrete differential geometry, it is widely believed that the discrete Gaussian curvature of a polyhedral vertex star equals the algebraic area of its Gauss image. However, no complete proof has yet been described. We present an elementary proof in which we compare, for a particular normal vector, its winding numbe…

2019-09-19abs ↗pdf ↗

Formula derived for Laplace-Beltrami spectrum on homogeneous spaces.

problem Calculating the spectrum of the Laplace-Beltrami operator on homogeneous spaces.
method Formula derivation based on eigenvalues of a generalized Casimir operator and spherical representations.
result First detailed computation and investigation of the spectrum for a family of metrics on the Aloff-Wallach manifold.

For a convex domain DD bounded by the hypersurface D\partial D in a space of constant curvature we give sharp bounds on the width RrR-r of a spherical shell with radii RR and rr that can enclose D\partial D, provided that normal curvatures of D\partial D are pinched by two positive constants. Furthermore, in the …

2014-02-11abs ↗pdf ↗

The study examines stability of triharmonic hypersurfaces in space forms.

problem Stability of triharmonic hypersurfaces in space forms.
method Derivation of general stability statements, focus on specific cases of constant mean curvature in Euclidean and hyperbolic spaces, and analysis of small proper triharmonic hyperspheres and Clifford tori.
result Triharmonic hypersurfaces of constant mean curvature in Euclidean space are weakly stable with respect to normal variations, while in hyperbolic space they are stable.

3D dust map of the Milky Way improves resolution and accuracy.

problem Reconstructing the 3D dust distribution in the Milky Way.
method Gaussian process regression on spherical coordinates with iterative grid refinement.
result Improved 3D dust map with increased resolution and accuracy.

New spherical Milnor spaces for diffeological groups with geometric and topological properties.

problem Understanding higher topological structures in diffeological spaces.
method Spherical Milnor construction based on quadratic normalization.
result Provides a natural setting for studying principal bundles with Z2\mathbb{Z}_2-twists and higher cohomology.

Study free energy in spherical spin glasses, proving universality dichotomy.

problem Analyzing free energy in spherical spin glass models with different tail exponents.
method Introduced a tail-adapted normalization and used universality dichotomy.
result Sharp universality dichotomy for free energy across different tail exponents.

Some new differentiable sphere theorems are obtained via the Ricci flow and stable currents. We prove that if MnM^n is a compact manifold whose normalized scalar curvature and sectional curvature satisfy the pointwise pinching condition R0>σnKmaxR_0>σ_{n}K_{\max}, where σn(14,1)σ_n\in (\frac{1}{4},1) is an explicit positive constan…

2011-02-11abs ↗pdf ↗

Study of immersions with Willmore energy leading to spherical and catenoid bubbles.

problem Classifying immersions with specific energy properties.
method Analyzing sequences of weak immersions with diverging conformal classes, applying Möbius transformations, and strong Wloc2,2W^{2,2}_{\mathrm{loc}}-limits.
result Obtaining spherical and catenoid bubbles as limits of immersions.

The paper studies the topology of spherical tori with one conical point.

problem Determining the topology of surfaces with constant curvature and conical points.
method Analyzing the moduli space of genus one surfaces with a conical point of specific angles.
result The moduli space topology depends on the integer m>0m>0 for ϑ(2m1,2m+1)\vartheta\in (2m-1,2m+1), and it has a complex structure for ϑ=2m\vartheta=2m.

For hypersurfaces of dimension greater than one, Huisken showed that compact self-shrinkers of the mean curvature flow with positive scalar mean curvature are spheres. We will prove the following extension: A compact self-similar solution in arbitrary codimension and of dimension greater than one is spherical, i.e. con…

2005-07-15abs ↗pdf ↗

Paper characterizes DLN distribution, its properties, and estimation methods.

problem No specific problem stated, focuses on DLN distribution properties.
method Characterization of PDF, CDF, moments; generalization to N-dimensions; methods to handle double-exponential nature.
result Characterization of DLN distribution and its properties, including estimation methods.

The study classifies horo-shrinkers in hyperbolic space under different isometries.

problem Characterizing horo-shrinkers in hyperbolic space under various isometries.
method Analyzing horo-shrinkers invariant by one-parameter groups of hyperbolic, parabolic, and spherical isometries.
result Grim reapers are defined as horo-shrinkers invariant by parabolic translations and are periodic surfaces.

Study stable capillary hypersurfaces with planar boundaries in half-spaces and domains.

problem Characterize stable capillary hypersurfaces with planar boundaries in bounded domains.
method Analyzes hypersurfaces in half-spaces and domains bounded by hyperplanes, proving conditions for stability and shape.
result Stable hypersurfaces in certain domains are spherical caps or pieces of spheres.

A new method for speaker recognition on hyperspheres improves on PLDA's limitations.

problem Improving speaker recognition on hyperspheres with PLDA's limitations.
method Probabilistic Spherical Discriminant Analysis (PSDA) using Von Mises-Fisher distributions.
result PSDA scores are closed-form and can handle various trials, improving over PLDA.

Under mean radius of curvature flow, a closed convex surface in Euclidean space is known to expand exponentially to infinity. In the 3-dimensional case we prove that the oriented normals to the flowing surface converge to the oriented normals of a round sphere whose centre is determined by the initial surface. To prove…

2013-10-16abs ↗pdf ↗