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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.

168,694 papers · 148 categories

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3672108144 · Jun 202019922001200920172026
48 results for non-separable kernels

New non-separable covariance kernels for spatiotemporal data derived from harmonic oscillator physics.

problem Capturing complex spatiotemporal dependencies in Gaussian processes.
method Hybrid spectral method based on the harmonic oscillator, deriving explicit covariance kernels.
result Explicit non-separable covariance kernels with space-time interactions.

New constructions from non-separating planar graphs improve understanding of graph linkability and knotability.

problem Understanding linkability and knotability of graph complements.
method Using maximal non-separating planar graphs to construct examples of maximal linkless and knotless graphs, and analyzing their Colin de Verdière invariant.
result The Colin de Verdière invariant of the complement of a maximal non-separating planar graph satisfies μ(cG) ≤ n-4, and equality holds.

The complement of a non-separating planar graph contains a K_n minor.

problem Characterizing the structure of complements of planar graphs.
method Analyzing the structure of complements of non-separating planar graphs and using examples to illustrate hypotheses.
result The order 2n-3 is the lowest possible for a non-separating planar graph whose complement contains a K_n minor.

Paper examines Dehn twists on non-orientable surfaces and their limitations.

problem Limitations of generating Dehn twists on non-orientable surfaces.
method Analyzes the level 2 mapping class group of non-orientable surfaces and their subgroups.
result Dehn twist subgroup of M2(Ng)\mathcal{M}_2(N_g) cannot be generated by squares of Dehn twists about non-separating curves.

A non-separating multicurve of a surface S of genus g with m punctures is a multicurve c so that S-c is connected. For k>0 define the graph of non-separting k-multicurves to be the graph whose vertices are non-separating multicurves with k components and where two such multicurves are connected by an edge if they can b…

2013-04-16abs ↗pdf ↗

Paper proves Torelli group's finiteness for surfaces with 2 boundaries.

problem Finiteness of Torelli group for surfaces with 2 boundaries.
method Analyzes Torelli group properties for surfaces of genus ≥ 3 with 2 boundary components.
result Torelli group is finitely generated for surfaces of genus ≥ 3 with 2 boundaries.

Study shortest non-separating curves on non-orientable surfaces, proving NP-hardness and tractability.

problem Computing shortest non-separating simple closed curves on non-orientable surfaces.
method Developed tools for computing shortest curves, proving NP-hardness and tractability.
result Proved NP-hardness and fixed-parameter tractability for computing shortest orienting curves, and polynomial-time algorithm for non-orienting curves.

Gradient descent converges to perfect classification in neural nets for non-separable data.

problem Classifying linearly non-separable data using neural networks.
method Analysis of gradient descent dynamics in neural networks with sufficient but not large number of neurons.
result Gradient descent converges to global minima with perfect classification in the landscape of minimization problems.

We derive and analyze a new, efficient, pool-based active learning algorithm for halfspaces, called ALuMA. Most previous algorithms show exponential improvement in the label complexity assuming that the distribution over the instance space is close to uniform. This assumption rarely holds in practical applications. Ins…

2011-12-07abs ↗pdf ↗

For n >2, we shall show that the group Aut(NS(M)) of simplicial automorphisms of the complex NS(M) of non-separating embedded spheres in the manifold M,connected sum of n copies of S^2 X S^1, isomorphic to the group Out(F_n) of outer automorphisms of the free group F_n, where FnF_n is identified with the fundamental gr…

2012-04-02abs ↗pdf ↗

The paper proves local laws for non-separable sample covariance matrices.

problem Analyzing non-separable sample covariance matrices with dependent or nonlinearly transformed data.
method Tensor network framework for analyzing fluctuation averaging in the presence of higher-order cumulant structure.
result Optimal averaged local law and full anisotropic local law for non-separable sample covariance matrices.

We prove integral rigidity for Seiberg-Witten invariants of 4-manifolds with specific hypersurfaces.

problem Integral rigidity of Seiberg-Witten invariants in 4-manifolds with non-separating hypersurfaces.
method Floer theoretic conditions and interplay between irreducible and reducible solutions to Seiberg-Witten equations.
result Sum of Seiberg-Witten invariants is determined cohomologically for specific 4-manifolds.

Develops flexible non-parametric ACFs using B-spline kernels.

problem Flexible modelling of the autocovariance function (ACF) in time-series, spatial, and spatio-temporal analysis.
method Derives the inverse Fourier transform of B-spline spectral bases to create a general class of non-parametric ACFs.
result Provides a provably dense, flexible, and general class of non-parametric ACFs for various types of processes.

In the curve complex for a surface, a handlebody set is the set of loops that bound properly embedded disks in a given handlebody bounded by the surface. A boundary set is the set of non-separating loops in the curve complex that bound two-sided, properly embedded surfaces. For a Heegaard splitting, the distance betwee…

2007-07-04abs ↗pdf ↗

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.

For an infinite cardinal κκ let 2(κ)\ell_2(κ) be the linear hull of the standard othonormal base of the Hilbert space 2(κ)\ell_2(κ) of density κκ. We prove that a non-separable convex subset XX of density κκ in a locally convex linear metric space if homeomorphic to the space (i) 2f(κ)\ell_2^f(κ) if and only if XX can be…

2013-05-07abs ↗pdf ↗

The unknot U in S^4 has non-unique smooth spanning 3-balls up to isotopy fixing U. Equivalently there are properly embedded non-separating 3-balls in S^1xB^3 not properly isotopic to 1xB^3. More generally there exist non-separating 3-spheres in S^1xS^3 not isotopic to 1xS^3 and non trivial elements of π_0 Diff_0(S^1xS^…

2019-12-19abs ↗pdf ↗

We generalize the classical Szpiro inequality to the case of a semistable family of hyperelliptic curves. We show that for a semistable symplectic Lefschetz fibration of hyperelliptic curves of genus gg, the number NN of non-separating vanishing cycles and the number DD of singular fibers satisfy the inequality $N \…

2001-06-25abs ↗pdf ↗

We present a necessary and sufficient condition for existence of a contractible, non-separating and noncontractible separating Hamiltonian cycle in the edge graph of polyhedral maps on surfaces. In particular, we show the existence of contractible Hamiltonian cycle in equivelar triangulated maps. We also present an alg…

2014-05-07abs ↗pdf ↗

In her seminal 2008 paper, Maryam Mirzakhani showed that the ratio that two topological types of curves occur in is a rational number. In this paper we describe the process by which we obtained experimental evidence that separating and non-separating curves on the surface of genus two occur in the ratio 1 : 48.

2019-10-17abs ↗pdf ↗

Modifying the method of [21], we compute the perturbed HF+HF^+ for some special classes of fibered three manifolds in the second highest spinc^c-structures Sg2S_{g-2}. The special classes considered in this paper include the mapping tori of Dehn twists along a single non-separating curve and along a transverse pair of c…

2009-03-02abs ↗pdf ↗

We show that a Hitchin representation is determined by the spectral radii of the images of simple, non-separating closed curves. As a consequence, we classify isometries of the intersection function on Hitchin components of dimension 3 and on the self-dual Hitchin components in all dimensions. As an important tool in t…

2017-03-21abs ↗pdf ↗

AMP algorithm for matrix tensor product model provides recovery conditions.

problem Generalization of standard spiked matrix models with multiple pairwise observations.
method Approximate message passing with optimal weighing and combining of estimates.
result Asymptotically exact performance description and necessary/sufficient recovery conditions.

DeepRV accelerates spatiotemporal inference using neural priors.

problem Intractable scaling of Gaussian Processes for large datasets.
method Neural-network surrogate replacing GP prior sampling with O(N2)O(N^2) complexity.
result DeepRV achieves highest fidelity to exact GPs while significantly speeding up inference.