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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.

168,742 papers · 148 categories

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59117176234 · Jun 202019922001200920172026
48 results for Low-order statistics

The paper introduces a frequency-domain estimator for low-order systems from noisy data.

problem Estimating frequency responses of low-order systems from noisy measurements.
method Uses a quadratic data-fitting term regularized by the nuclear norm of a Loewner matrix, subject to a convex stability constraint.
result Proves a finite-sample error bound and extends it to all frequencies through rational interpolation.

The paper tackles system identification via Hankel nuclear norm regularization, improving estimation rates and singular value gaps.

problem Identifying low-order linear systems from limited data.
method Hankel nuclear norm regularization to encourage low-rankness of the Hankel matrix.
result Hankel regularization enables optimal system recovery with fewer observations and better estimation rates.

New framework detects out-of-distribution samples efficiently.

problem Detecting samples from different distributions in deep neural networks.
method Statistical hypothesis testing framework combining evidence from entire network.
result Framework maintains Type I Error and achieves comparable results to state-of-the-art methods.

Algorithm learns causal structures from low-order conditional independencies.

problem Estimating high-order conditional independencies from data is challenging.
method Proposes an algorithm to compute a faithful graphical representation from low-order conditional independencies.
result Algorithm successfully learns causal structures from zero- and first-order conditional independencies.

Bayesian method improves EEG source imaging accuracy by estimating skull conductivity.

problem Sensitivity of EEG source imaging to skull conductivity modeling.
method Bayesian uncertainty modeling to estimate skull conductivity and focal sources.
result Clear improvements in source localization accuracy and feasible skull conductivity estimates.

We consider the problem of computing first-passage time distributions for reaction processes modelled by master equations. We show that this generally intractable class of problems is equivalent to a sequential Bayesian inference problem for an auxiliary observation process. The solution can be approximated efficiently…

2017-06-01abs ↗pdf ↗

Efficient algorithm for matching graphs with community structure.

problem Graph matching between correlated stochastic block models with constant correlation.
method Partition trees rooted from each vertex, comparing edge statistics to different communities.
result First low-order polynomial-time algorithm achieving exact matching with high probability in dense graphs.

Optimizes mixture models without parametrizing distributions using tensor decomposition.

problem Estimating conditionally-independent mixture models in high dimensions.
method Alternating least squares optimization scheme for tensor decomposition.
result Competitive performance and applicability to various models and applications.

Principal components analysis (PCA) is the optimal linear auto-encoder of data, and it is often used to construct features. Enforcing sparsity on the principal components can promote better generalization, while improving the interpretability of the features. We study the problem of constructing optimal sparse linear a…

2015-02-23abs ↗pdf ↗

Paper studies statistical-computational trade-offs in tensor PCA and related problems.

problem Statistical-computational gap in tensor PCA estimation.
method Derives computational lower bounds using communication complexity.
result Lower bounds specify trade-off among passes, sample size, and memory.

With higher-order neighborhood information of graph network, the accuracy of graph representation learning classification can be significantly improved. However, the current higher order graph convolutional network has a large number of parameters and high computational complexity. Therefore, we propose a Hybrid Lower …

2019-08-02abs ↗pdf ↗

Using the classification of transitive groups we classify indecomposable quandles of size <36. This classification is available in Rig, a GAP package for computations related to racks and quandles. As an application, the list of all indecomposable quandles of size <36 not of type D is computed.

2011-05-26abs ↗pdf ↗

We introduce and study new invariants associated with Laplace type elliptic partial differential operators on manifolds. These invariants are constructed by using the off-diagonal heat kernel; they are not pure spectral invariants, that is, they depend not only on the eigenvalues but also on the corresponding eigenfunc…

2014-08-10abs ↗pdf ↗

Researchers prove long-time existence for two landmark Brownian motion.

problem Proving long-time existence of Brownian motion on configurations of two landmarks.
method Classification and analysis of long-time existence for configurations of exactly two landmarks, using a radial kernel.
result For configurations of exactly two landmarks, long-time existence is possible for certain kernels, but not for others.

Bayesian method combines data assimilation, machine learning, and EM for chaotic dynamics.

problem Reconstructing high-dimensional chaotic dynamics from noisy, partial observations over long time series.
method Bayesian inference using expectation-maximization and coordinate descent.
result Successfully tested on two chaotic models, estimating model, state trajectory, and model error statistics.

This work considers a computationally and statistically efficient parameter estimation method for a wide class of latent variable models---including Gaussian mixture models, hidden Markov models, and latent Dirichlet allocation---which exploits a certain tensor structure in their low-order observable moments (typically…

2012-10-29abs ↗pdf ↗

We develop a systematic method for classifying supersymmetric orbifold compactifications of M-theory. By restricting our attention to abelian orbifolds with low order, in the special cases where elements do not include coordinate shifts, we construct a "periodic table" of such compactifications, organized according to …

2002-08-04abs ↗pdf ↗

Study local equivalence of Riemannian submersions using differential invariants.

problem Local equivalence problem for Riemannian submersions under fiber-preserving isometries.
method Analysis of differential invariants for orbit submersions induced by a Killing field.
result Explicit formulas for AA and HH in terms of base data (gˉ,φ,Ω)(\bar g,\varphi,Ω) and equivalence criterion.

Hermite polynomials improve private data generation by reducing feature count.

problem Infinite-dimensional features in kernel mean embedding are impractical for private data generation.
method Replace random features with Hermite polynomial features, leveraging their ordered nature.
result Hermite polynomial features yield a more accurate approximation of kernel mean embedding with fewer features.

Study how neural networks learn from non-Gaussian data models.

problem Understanding neural network learning dynamics with non-Gaussian data.
method Developed a two-layer neural network with Hermite polynomial activations to control high-order cumulants.
result Neural networks progressively learn high-order cumulants after capturing low-order statistics.

New framework uses score-based priors to solve ill-conditioned polynomial equations, improving signal recovery from noisy data.

problem Recovering signals from low-order moments in inverse problems, especially ill-conditioned polynomial equations.
method Integrates score-based diffusion priors with moment-based estimators to regularize and solve nonlinear inverse problems.
result Diffusion priors improve recovery from third-order moments and make super-resolution MTD feasible.

New SQ lower bounds for NGCA without requiring chi-squared condition.

problem Proving SQ hardness for NGCA under moment-matching conditions.
method General SQ lower bound methodology applied to NGCA under moment-matching conditions.
result Proved near-optimal SQ lower bounds for NGCA without chi-squared condition.

We introduce a notion of ternary distributive algebraic structure, give examples, and relate it to the notion of a quandle. Classification is given for low order structures of this type. Constructions of such structures from ternary bialgebras are provided. We also describe ternary distributive algebraic structures com…

2014-03-27abs ↗pdf ↗

Bayes-optimal limits in PCA with structured noise are determined.

problem Analyzing statistical dependencies in measurement noise for high-dimensional inference.
method Study of spiked matrix model with low-order polynomial orthogonal noise, providing Bayes-optimal limits and proposing a novel AMP.
result A novel AMP algorithm reaches the information-theoretic limits for more general priors.

We consider the inverse Ising problem, i.e. the inference of network couplings from observed spin trajectories for a model with continuous time Glauber dynamics. By introducing two sets of auxiliary latent random variables we render the likelihood into a form, which allows for simple iterative inference algorithms with…

2017-09-04abs ↗pdf ↗

We define and study Vassiliev invariants for (long) Morse knots. It is shown that there are Vassiliev invariants which can distinguish some topologically equivalent Morse knots. In particular, there is an invariant of order 3 for Morse knots with one maximum that distinguishes two different representations of the figur…

2000-08-13abs ↗pdf ↗

We classify invariant Lagrangians of the form L(gij,gij,k,gij,kl,DI,DI,j)L(g_{ij},g_{ij,k},g_{ij,kl},D_I,D_{I,j}) depending at most quadratically on the variables gij,k,gij,klg_{ij,k},g_{ij,kl} and DI,DI,jD_I,D_{I,j}, where gg is a Lorentz metric and DD is a tensor field of arbitrary rank on a smooth manifold. As a corollary, we prove a conjecture of Bray'…

2014-08-18abs ↗pdf ↗

The objective of this paper is to investigate how noisy and incomplete observations can be integrated in the process of building a reduced-order model. This problematic arises in many scientific domains where there exists a need for accurate low-order descriptions of highly-complex phenomena, which can not be directly …

2015-10-08abs ↗pdf ↗

A new method interprets astrophysical spectra using geometric paths to distinguish line profiles.

problem Tackling the indistinguishability of spectral line profiles under scalar summaries.
method Introduces a geometric representation of line profiles using rough path theory, mapping profiles to a common velocity grid and defining descriptors from path properties.
result Compact descriptors separate morphologies with similar scalar summaries, revealing ordered line structures.

TopoFisher learns topological summaries by maximizing Fisher information, improving parameter efficiency and inference quality.

problem Simulation-based inference misses key information in low-order statistics, especially for non-Gaussian fields.
method TopoFisher uses a differentiable persistent-homology pipeline that learns topological summaries by maximizing local Gaussian Fisher information.
result TopoFisher recovers much of the available information and outperforms fixed topological vectorizations in weak gravitational lensing.

The problem of topic modeling can be seen as a generalization of the clustering problem, in that it posits that observations are generated due to multiple latent factors (e.g., the words in each document are generated as a mixture of several active topics, as opposed to just one). This increased representational power …

2012-04-30abs ↗pdf ↗

Notes on Whitney towers in 4-manifolds, focusing on local surface manipulations and invariants.

problem Classifying and understanding Whitney towers in 4-manifolds.
method Local manipulations of surfaces, definitions of Whitney towers and trees, geometric Jacobi identities, classification of twisted Whitney towers.
result Classification of order n twisted Whitney towers in the 4-ball and related invariants.

Corrected moment-based methods improve inference in topic model regression.

problem Inferential difficulties in topic model plug-in workflow for regression.
method Corrected spectral moment methods for LDA, response-weighted word moments.
result Direct identification of regression coefficients without estimating topic shares.