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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

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137274411548 · Jun 202019922001200920172026
48 results for thick distributions

The paper introduces boundary thickness as a measure for improving model robustness.

problem Improving the robustness of machine learning models to adversarial and non-adversarial corruptions.
method Introducing boundary thickness as a measure and showing how various procedures can increase it.
result Thicker decision boundaries lead to improved robustness against adversarial and out-of-distribution transforms.

Let MM be a finite volume oriented Riemannian manifold of dimension n3n\geq 3 and curvature in [b2,1][-b^2,-1], with thick-thin decomposition M=M(thick)M(thin)M=M(thick)\cup M(thin). Denote by λk(M(thick))λ_k(M(thick)) the k-th eigenvalue for the Laplacian on M(thick)M(thick), with Neumann boundary conditdions. We show that λk(M(thick))/3λk(M)λ_k(M(thick))/3\leq λ_k(M)

2018-10-11abs ↗pdf ↗

What length of rope (of given diameter) is required to tie a particular knot? To answer this question, we define some new notions of thickness for a space curve, one based on Gromov's distortion, and another generalizing the thickness of Litherland, Simon et al. We prove a basic inequality between these thickness measu…

1997-02-04abs ↗pdf ↗

Method estimates section thickness and XY anisotropy in ssEM images.

problem Accurate 3D reconstructions require precise section thickness and XY anisotropy estimates.
method Non-parametric Bayesian regression of image statistics.
result Method has lower estimation error compared to existing methods.

For right-angled Coxeter groups WΓW_Γ, we obtain a condition on ΓΓ that is necessary and sufficient to ensure that WΓW_Γ is thick and thus not relatively hyperbolic. We show that Coxeter groups which are not thick all admit canonical minimal relatively hyperbolic structures; further, we show that in such a structure, …

2013-12-17abs ↗pdf ↗

We describe some problems, observations, and conjectures concerning thickness and packing density of knots and links in $\sp^3$ and R3\R^3. We prove the thickness of a nontrivial knot or link in $\sp^3$ is no more than π4\fracπ{4}, the thickness of a Hopf link. We also give arguments and evidence supporting the conject…

2002-03-28abs ↗pdf ↗

The paper explores new algebraic structures and morphisms in graded settings.

problem Understanding new algebraic structures and morphisms in graded settings.
method Introducing and analyzing LL_{\infty}-, PP_{\infty}-, and SS_{\infty}-algebras, and thick morphisms in a Z2imesZ\mathbb{Z}_2 imes \mathbb{Z}-graded context.
result Shifted SS_{\infty}-thick morphisms induce LL_{\infty}-morphisms of shifted SS_{\infty}-structures.

We show that the diameter of the skinning map of an acylindrical hyperbolic 3-manifold M is bounded on thick Teichmueller geodesic rays by a constant depending only on the thickness of the ray and the topological type of the boundary of M.

2018-03-26abs ↗pdf ↗

We show that a complete hyperbolic n-manifold has a geodesic triangulation such that the tetrahedra contained in the thick part are L-bilipschitz diffeomorphic to the standard Euclidean n-simplex, for some constant L depending only on the dimension and the constant used to define the thick-thin decomposition of M.

2007-11-01abs ↗pdf ↗

Study on reducing surgeries on knots, developing thickness and genus bounds.

problem Understanding reducible surgeries on knots in S3S^3.
method Developed thickness bounds for L-space knots and lower bounds on slice genus; used dd-invariants and mapping cone formula from Heegaard Floer homology.
result Provided new upper bounds on reducing slopes for fibered, hyperbolic slice knots and on multiple reducing slopes for slice knots; verified the Cabling Conjecture for thin knots.

We prove that thick groups (and more generally thick graphs) have trivial Floyd boundary. This shows a wide class of finitely generated groups that are non-relatively hyperbolic have trivial Floyd boundary. In addition to giving new examples, our result provides a common proof and framework for many of the known result…

2018-11-30abs ↗pdf ↗

We show the existence of a thick thin decomposition of the domain of a pseudo holomorphic curve with boundary. The geometry of the thick part is bounded uniformly in the energy. Furthermore, in the thick part, there is a uniform bound on the differential which is exponential in the energy. The thin part consists of ann…

2013-11-29abs ↗pdf ↗

We introduce the notion of connection thickness of spheres in a Cayley graph, related to dead-ends and their retreat depth. It was well-known that connection thickness is bounded for finitely presented one-ended groups. We compute that for natural generating sets of lamplighter groups on a line or on a tree, connection…

2016-06-08abs ↗pdf ↗

A graphical calculus for microformal morphisms simplifies complex operations in classical and quantum physics.

problem Simplifying operations in classical and quantum microformal morphisms.
method Developed a graphical calculus inspired by Cattaneo-Dherin-Felder's work on formal symplectic groupoids, extended to quantum thick morphisms.
result Infinite series can be written as sums over bipartite trees for both classical and quantum thick morphisms.

Classifies divergence and thickness in right-angled Coxeter groups.

problem Characterizing the divergence and thickness of right-angled Coxeter groups.
method Completely classifies divergence functions and proves conditions for thickness using the hypergraph index.
result Exact divergence functions of RACGs can be computed from their defining graphs.

A robust Gaussian process model using Huber likelihood for outlier resistance.

problem Outliers in observational data sets affect Gaussian process regression's robustness.
method Proposes a Gaussian process model with Huber likelihood and weights based on projection statistics.
result Demonstrates improved statistical efficiency and robustness to outliers.

We investigate the relationship between a discrete version of thickness and its smooth counterpart. These discrete energies are defined on equilateral polygons with nn vertices. It will turn out that the smooth ropelength, which is the scale invariant quotient of length divided by thickness, is the ΓΓ-limit of the di…

2014-01-22abs ↗pdf ↗

Geodesic currents on surfaces have comparable metrics in thick regions.

problem Comparing the geometry of geodesic currents and their minimizing metrics.
method Analyzing the space of geodesic currents on surfaces and comparing metrics on thick components.
result Geometries of geodesic currents and their minimizing metrics are comparable in thick regions.

Study on divergence and thickness for Coxeter groups, generalizing previous work.

problem Characterizing and bounding divergence and thickness for Coxeter groups.
method Characterization of linear divergence, introduction of hypergraph index, new construction of Coxeter systems.
result Upper bounds on divergence and thickness for Coxeter groups, conjectured to be equalities.

Infinite volume found in the thick part of PSLn(R)\mathrm{PSL}_n(\mathbb{R})-Hitchin-Riemann moduli space.

problem Proving infinite volume in the thick part of PSLn(R)\mathrm{PSL}_n(\mathbb{R})-Hitchin-Riemann moduli space.
method Employing Goldman flows and internal sequences to find an infinite series of subsets of identical volume.
result Infinite total Atiyah--Bott--Goldman volume for n>2n>2.

Study differential operators over maps and their applications in supermanifolds.

problem Understanding differential operators over smooth maps and their applications.
method Recall and study differential operators, formal \hbar-differential operators, pullbacks by thick morphisms, and quantization of symplectic micromorphisms.
result Developed constructions and examples of differential operators over maps.

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 ↗

Study of cable links of uniformly thick knots, revealing new isotopy phenomena.

problem Understanding Legendrian isotopy in cable links of uniformly thick knots.
method Introduced new technique of Legendrian surgeries to classify Legendrian knots in negative cables of twist knots.
result Found new phenomena of stabilized Legendrian links that are smoothly isotopic but not Legendrian isotopic.

We review and organize some results describing the behavior of a Teichmüller geodesic and draw several applications: 1) We show that Teichmüller geodesics do not back track. 2) We show that a Teichmüller geodesic segment whose endpoints are in the thick part has the fellow travelling property. This fails when the endpo…

2010-11-27abs ↗pdf ↗

For purposes of Value-at-Risk estimation, we consider several multivariate families of heavy-tailed distributions, which can be seen as multidimensional versions of Paretian stable and Student's t distributions allowing different marginals to have different tail thickness. After a discussion of relevant estimation and …

2010-05-17abs ↗pdf ↗

Heavy-tailed distributions are widely used in robust mixture modelling due to possessing thick tails. As a computationally tractable subclass of the stable distributions, sub-Gaussian αα-stable distribution received much interest in the literature. Here, we introduce a type of expectation maximization algorithm that e…

2017-01-24abs ↗pdf ↗

Study of Milnor invariants and ropelength of spherical links.

problem Understanding the relationship between the thickness of spherical links and their Milnor invariants.
method Generalized Massey products and Milnor invariants to spherical links, finding optimal asymptotic bounds.
result Optimal asymptotic bounds on Milnor invariants in terms of thickness, revealing a polynomial vs exponential regime.

The paper finds the unique minimizer of area for hyperbolic bodies with curvature constraints.

problem Finding the unique minimizer of area for hyperbolic bodies with curvature constraints.
method Introduced the concept of 'thick λλ-sausage' bodies and used extra assumption of thickness to handle non-convex inner parallel bodies.
result The thick λλ-sausage body is the unique minimizer of area among all bodies with a given length and curvature constraints.

Nonuniform tubular neighborhoods of curves in Euclidean n-space are studied by using weighted distance functions and generalizing the normal exponential map. Different notions of injectivity radii are introduced to investigate singular but injective exponential maps. A generalization of the thickness formula is obtaine…

2007-05-16abs ↗pdf ↗