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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.

168,695 papers · 148 categories

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56112168224 · Jun 202019922001200920172026
48 results for t-factor analyzers

Develops a hybrid MtFA approach for high-dimensional data clustering.

problem Scalability issues in traditional MtFA estimation methods for high-dimensional data.
method Integrates profile likelihood method into EM framework for efficient parameter estimation.
result Demonstrates superior computational efficiency and clustering accuracy compared to existing methods.

A mixture of common skew-t factor analyzers model is introduced for model-based clustering of high-dimensional data. By assuming common component factor loadings, this model allows clustering to be performed in the presence of a large number of mixture components or when the number of dimensions is too large to be well…

2013-07-21abs ↗pdf ↗

We study the linear contextual bandit problem with finite action sets. When the problem dimension is dd, the time horizon is TT, and there are n2d/2n \leq 2^{d/2} candidate actions per time period, we (1) show that the minimax expected regret is Ω(dT(logT)(logn))Ω(\sqrt{dT (\log T) (\log n)}) for every algorithm, and (2) introduce a V…

2019-03-30abs ↗pdf ↗

We consider the problem of Bayesian optimization (BO) in one dimension, under a Gaussian process prior and Gaussian sampling noise. We provide a theoretical analysis showing that, under fairly mild technical assumptions on the kernel, the best possible cumulative regret up to time TT behaves as Ω(T)Ω(\sqrt{T}) and $O(\s…

2018-05-30abs ↗pdf ↗

We study the stochastic multi-armed bandit problem in the case when the arm samples are dependent over time and generated from so-called weak $\cC$-mixing processes. We establish a $\cC-$Mix Improved UCB agorithm and provide both problem-dependent and independent regret analysis in two different scenarios. In the first…

2019-06-25abs ↗pdf ↗

Study online pricing with contextual elasticity and heteroscedastic valuation.

problem Online contextual dynamic pricing with customer decision based on features and price.
method Introduced a novel approach to modeling customer demand with feature-based price elasticity and heteroscedastic noise. Proposed an efficient algorithm called Pricing with Perturbation (PwP).
result Proved an O(dTlogT)O(\sqrt{dT\log T}) regret bound for the algorithm, matching a lower bound of Ω(dT)Ω(\sqrt{dT}).

VI struggles to fully quantify uncertainty when distributions don't factorize.

problem Uncertainty quantification in non-factorizable distributions.
method Analysis of variational inference trade-offs and divergence choices.
result Different divergences yield different measures of uncertainty in VI.

Enhances RL with function approximation, improving regret bounds.

problem Improving exploration in reinforcement learning with function approximation.
method Prior-dependent Bayesian regret bound for PSRL with linear mixture MDPs, using value-targeted model learning and variance reduction.
result Established an upper bound of O(dH3TlogT){\mathcal{O}}(d\sqrt{H^3 T \log T}) for PSRL.

Efficient algorithms for online convex optimization with limited switching decisions.

problem Online convex optimization with limited switching decisions.
method Presented computationally efficient algorithms for both general and strongly convex losses.
result Regret bounds of O(T/S)O(T/S) for general convex losses and O~(T/S2)\widetilde O(T/S^2) for strongly convex losses.

Study on adaptivity constraints in linear contextual bandits with optimal design.

problem Impact of adaptivity constraints on linear contextual bandits.
method Two models of limited adaptivity: batch learning and rare policy switches. Proposed distributional optimal design.
result Achieves minimax-optimal regret with optimal number of policy switches and batches.

The paper improves bounds on regret in Gaussian process bandits.

problem Sequential optimization of expensive, possibly non-convex functions with noisy feedback.
method Analyzes maximal information gain and decay rates of GP kernel eigenvalues to improve regret bounds.
result General bounds on maximal information gain and improved regret bounds for various settings, including Matérn kernels.

Reduces IB problem to a simpler, lower-dimensional problem.

problem Information bottleneck problem in high-dimensional spaces.
method Identifies sufficient statistic that factors conditional distribution, reducing IB to a lower-dimensional problem.
result Preserves full IB curve and optimal representations, making IB tractable.

New algorithm ensures replicable results in multi-armed bandits with minimal extra regret.

problem Ensuring consistent results in multi-armed bandit studies.
method Incorporates randomness into decision-making to ensure replicability while maintaining minimal extra regret.
result For large time horizons, proposed algorithm suffers only K2/ρ2K^2/ρ^2 times smaller amount of exploration than existing algorithms.

Bayesian VI copula models capture asymmetric intraday equity dependence.

problem Modeling asymmetric and extreme tail dependence in financial data.
method Bayesian variational inference for skew-t copula models in high dimensions.
result The copula captures substantial heterogeneity in asymmetric dependence over equity pairs and time.

Paper proposes an online learning method with multi-level adaptivity for diverse loss functions.

problem Online learning with unknown types and curvatures of functions.
method Multi-layer online ensemble approach with gradient variations.
result Achieves improved regret bounds for different types of loss functions.

A novel algorithm minimizes regret in a multi-agent bandit problem with time-varying random graphs and heterogeneous rewards.

problem Minimizing regret in a multi-agent multi-armed bandit problem with time-varying random graphs and heterogeneous rewards.
method Introduces a novel algorithmic framework combining averaging-based consensus with a weighting technique and upper confidence bound.
result Derives optimal instance-dependent regret upper bounds of order logT\log{T} in both sub-gaussian and sub-exponential environments.

In high frequency financial data not only returns but also waiting times between trades are random variables. In this work, we analyze the spectra of the waiting-time processes for tick-by-tick trades. The numerical problem, strictly related with the real inversion of Laplace transforms, is analyzed by using Tikhonov's…

2008-01-19abs ↗pdf ↗

With the help of transfer entropy, we analyze information flows between communities of complex networks. We show that the transfer entropy provides a coherent description of interactions between communities, including non-linear interactions. To put some flesh on the bare bones, we analyze transfer entropies between co…

2017-06-17abs ↗pdf ↗

A parsimonious model reduces over-parameterization in skewed matrix variate mixtures.

problem Over-parameterization in skewed matrix variate mixtures.
method Parsimonious family of 256 models using bilinear factor analyzers constrained over clusters, with AECM algorithm for estimation.
result Extensive simulations and real-world datasets (MNIST, Olivetti faces) demonstrate the method's effectiveness.

The paper analyzes sports commentary to automatically recognize events and extract insights.

problem Automatically recognizing and categorizing major actions in sports events from commentary.
method Used multiple Natural Language Processing techniques for classification and sentiment analysis.
result Identified insights from analyzing live sport commentaries and classifying major actions.

MSFA clusters high-dimensional spatial data using spline-based covariance structures.

problem Clustering high-dimensional spatial data with flexible covariance structures.
method Mixture of spatial factor analyzers with spline-based covariance and matrix variate factor analyzers for dimensionality reduction.
result Proposed models accurately infer and differentiate distinct spatial patterns in tensor-variate data.

Existing approaches to analyzing the asymptotics of graph Laplacians typically assume a well-behaved kernel function with smoothness assumptions. We remove the smoothness assumption and generalize the analysis of graph Laplacians to include previously unstudied graphs including kNN graphs. We also introduce a kernel-fr…

2011-01-28abs ↗pdf ↗

An approach is suggested for analyzing time series by means of resummation techniques of theoretical physics. A particular form of such an analysis, based on the algebraic self-similar renormalization, is developed and illustrated by several examples from the stock market time series.

1997-10-27abs ↗pdf ↗

The paper analyzes CycleGAN's error components for unpaired data generation.

problem Analyzing approximation and estimation errors in CycleGAN for unpaired data.
method Decomposes risk into approximation and estimation errors, analyzing each separately and considering their trade-offs.
result Theoretical insights into CycleGAN's performance through error analysis.

We introduce a scalable measure of curvature for analyzing training dynamics of large language models.

problem Analyzing the training dynamics of large language models due to high computational cost of measuring Hessian sharpness.
method We introduce critical sharpness and relative critical sharpness as computationally efficient measures capturing Hessian sharpness phenomena.
result We provide the first demonstration of sharpness phenomena at scale up to 7B parameters.

We describe for any Riemannian manifold a certain infinitesimal neighbourhood of the diagonal. Semi-conformal maps are analyzed as those that preserve such neighbourhoods; harmonic maps are analyzed as those that preserve mirror image formation for pairs of points in such neighbourhoods.

2003-06-12abs ↗pdf ↗

Paper analyzes and compares ELF algorithms for federated learning.

problem Improving efficiency and privacy in federated learning.
method Proposes P-ELF, D-ELF, and B-ELF algorithms with primal, dual, and bidirectional compression.
result Provides non-asymptotic convergence guarantees under Log-Sobolev inequality.

We analyze geometrical structures necessary to represent bulk and surface interactions of standard and substructural nature in complex bodies. Our attention is mainly focused on the influence of diffuse interfaces on sharp discontinuity surfaces. In analyzing this phenomenon, we prove the covariance of surface balances…

2004-06-18abs ↗pdf ↗

We analyze an ideal gas like models of a trading market. We propose a new fit for the money distribution in the fixed or uniform saving market. For the marketwith quenched random saving factors for its agents we show that the steady state income (mm) distribution P(m)P(m) in the model has a power law tail with Pareto in…

2005-05-06abs ↗pdf ↗

New method for analyzing learning dynamics in singular models.

problem Challenges in analyzing learning of singular models with no one-to-one parameter space.
method Relative reparameterization technique to extract regular sub-models.
result Demonstrated differences in convergence behavior due to algorithmic and intrinsic aspects.

Unified framework for analyzing online convex optimization across various settings.

problem Analyzing online convex optimization in different settings and feedback types.
method Unified framework allowing systematic proposal and analysis of meta-algorithms.
result Comparable regret bounds for various feedback types and adversary types.

We analyze a fast incremental aggregated gradient method for optimizing nonconvex problems of the form minxifi(x)\min_x \sum_i f_i(x). Specifically, we analyze the SAGA algorithm within an Incremental First-order Oracle framework, and show that it converges to a stationary point provably faster than both gradient descent and s…

2016-03-19abs ↗pdf ↗

By a fixed continuous map from a 33-space to itself, a knot in the 33-space may be mapped to another knot in the 33-space. We analyze possible knot types of them. Then we map a knot repeatedly by a fixed continuous map and analyze possible infinite sequences of knot types.

2014-09-01abs ↗pdf ↗

Analyzes multi-day stock returns, showing linear volatility and mean dependence.

problem Linear dependence of volatility and mean in accumulated stock returns.
method Modified Jones-Faddy skew t-distribution analysis.
result Linear dependence of volatility and mean on the number of days of accumulation.

The paper relaxes assumptions for analyzing stochastic optimization algorithms.

problem Analyzing the convergence of stochastic gradient algorithms under weaker variance assumptions.
method Building on and extending a connection to the Halpern iteration, the paper analyzes algorithms for convex nonsmooth optimization and min-max problems.
result Rates for optimality measures are obtained without requiring boundedness of the feasible set for problems beyond simple constrained optimization.

Online news media provides aggregated news and stories from different sources all over the world and up-to-date news coverage. The main goal of this study is to have a solution that considered as a homogeneous source for the news and to represent the news in a new conceptual framework. Furthermore, the user can easily …

2018-08-29abs ↗pdf ↗

Study uses ML and statistical models to analyze climate impacts of industrial growth.

problem Understanding and predicting environmental impacts of industrial activities.
method Comparative analysis of ML and statistical models on time series data.
result ML models outperform statistical models in predicting environmental impacts.