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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.

168,657 papers · 148 categories

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69138206275 · Jun 202019922001200920172026
48 results for sub-Gaussian rate

SVGD algorithm converges at rate 1/sqrt(log log n) for sub-Gaussian distributions.

problem Approximating a probability distribution with particles.
method Stein variational gradient descent (SVGD) with finite particles and sub-Gaussian target distribution.
result SVGD achieves a convergence rate of 1/sqrt(log log n) for sub-Gaussian distributions.

New study shows mean estimation algorithms can't beat sub-Gaussian rate in general.

problem Improving mean estimation beyond worst-case scenarios.
method Constructing counterexamples and introducing neighborhood optimality.
result No reasonable estimator can achieve better than sub-Gaussian error rate for any distribution.

Paper analyzes SGMs for learning sub-Gaussian distributions without dimensionality constraints.

problem Learning sub-Gaussian distributions in high dimensions with SGMs.
method Introduced complexity notion and proved approximation and generalization rates.
result SGMs can approximate target sub-Gaussian distributions in total variation with dimension-independent rate.

Paper analyzes neural network models for sub-Gaussian distributions, proving approximation and generalization abilities.

problem Estimating unknown distributions from i.i.d. observations using neural network models.
method Score-based neural network generative models (SGMs) with specific network architectures and stopping strategies.
result SGMs can approximate scores with high accuracy and achieve nearly optimal convergence rates under mild assumptions.

Efficiently estimates covariance for sub-Weibull vectors with sub-Gaussian rate.

problem Outliers in high-dimensional covariance estimation.
method Cross-Fitted Norm-Truncated Estimator for Sub-Weibull distributions.
result Achieves optimal sub-Gaussian rate with O(Nd2)O(Nd^2) operations.

We propose an estimator for the mean of a random vector in Rd\mathbb{R}^d that can be computed in time O(n4+n2d)O(n^4+n^2d) for nn i.i.d.~samples and that has error bounds matching the sub-Gaussian case. The only assumptions we make about the data distribution are that it has finite mean and covariance; in particular, we mak…

2019-02-06abs ↗pdf ↗

Paper proposes a 1-bit quantization scheme for high-dimensional statistical estimation.

problem High-dimensional statistical estimation with limited data.
method Uniformly dithered 1-bit quantization for sparse covariance matrix estimation, sparse linear regression, and matrix completion.
result Near minimax rates in sub-Gaussian regime and improved rates in heavy-tailed regime.

New method estimates hidden binary mixture model centers efficiently.

problem Estimating centers in high-dimensional binary mixture models with hidden Markov structure.
method Proposes a minimax optimal procedure and an adaptive variant.
result Achieves optimal rate of order δd/n+d/n\sqrt{δd/n} + d/n.

A new algorithm estimates mean adaptively to covariance, faster and more flexible than existing methods.

problem Estimating mean of a distribution with unknown covariance efficiently and privately.
method Adaptive differentially private algorithm with optimal convergence rates and near-linear sample complexity.
result Achieves optimal rates of convergence with respect to the Mahalanobis norm Σ||\cdot||_Σ.

We tackle the problem of estimating a location parameter with differential privacy guarantees and sub-Gaussian deviations. Recent work in statistics has focused on the study of estimators that achieve sub-Gaussian type deviations even for heavy tailed data. We revisit some of these estimators through the lens of differ…

2019-06-27abs ↗pdf ↗

We propose robust sparse reduced rank regression for analyzing large and complex high-dimensional data with heavy-tailed random noise. The proposed method is based on a convex relaxation of a rank- and sparsity-constrained non-convex optimization problem, which is then solved using the alternating direction method of m…

2018-10-18abs ↗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 ↗

Sharp sub-Gaussian bounds for subsolutions of Trudinger's equation on Riemannian manifolds.

problem Bounding weak subsolutions of Trudinger's equation on Riemannian manifolds.
method Proving sub-Gaussian upper bounds for weak subsolutions.
result The upper bounds are sharp for specific classes of manifolds, including \(\mathbb{R}^{n}\).

Study non-parametric frequency-domain system identification from finite samples.

problem Frequency-domain system identification from limited data.
method Empirical Transfer Function Estimate (ETFE) under sub-Gaussian colored noise and stability assumptions.
result ETFE estimates are concentrated around true values with a finite-sample rate of Ntot1/3N_{\mathrm{tot}}^{-1/3} for all frequencies in the H \mathcal{H}_{\infty} norm.

UCB algorithm adapted for large-scale, non-sub-Gaussian problems.

problem Selecting the best alternative from a large set of options with non-sub-Gaussian performance distributions.
method Adapted UCB algorithm for non-sub-Gaussian settings, focusing on sample size and meta-UCB selection.
result UCB algorithms can achieve sample optimality in large-scale, non-sub-Gaussian problems.

Proves new concentration inequalities for sub-gaussian and sub-exponential variables.

problem Understanding functions of independent random variables better.
method Sub-gaussian and sub-exponential conditions, Rademacher complexities, Lipschitz function classes.
result Extension of Rademacher complexities to unbounded sub-exponential distributions.

Paper presents robust clustering methods for general mixture models.

problem Clustering with sub-Gaussian error assumptions often invalid in practice.
method Hybrid clustering with robust centroid estimate and data-driven initialization.
result Provably near-optimal mislabeling guarantees for general error distributions.

Study improves self-normalized bounds for vector-valued processes beyond sub-Gaussianity.

problem Limited understanding of self-normalized concentration for vector-valued processes outside sub-Gaussian frameworks.
method Developed concentration inequalities for self-normalized processes with light tails (e.g., Bennett, Bernstein bounds) for vector-valued data.
result Provided new insights and bounds for self-normalized processes with non-sub-Gaussian distributions.

DP-PCA improves privacy in PCA computations with optimal statistical error.

problem Differentially private principal component analysis with sub-linear sample complexity.
method Private minibatch gradient ascent with private mean estimation.
result Achieves optimal statistical error rates for sub-Gaussian data with n=ildeO(d)n= ilde O(d) samples.

New algorithm converts data into sub-gaussian designs efficiently.

problem Efficiently converting large datasets into sub-gaussian random designs for robust performance.
method Algorithmic Gaussianization through sketching and averaging, using LESS embeddings.
result Efficient data sketches nearly indistinguishable from sub-gaussian designs.

The study examines conditions for achieving a simple lower bound in estimating mean from samples.

problem Achieving a simple lower bound for estimating the mean of a distribution.
method Analyzes conditions for nearly attaining Le Cam's two-point testing lower bound for mean estimation.
result An algorithm nearly attains the two-point testing rate for mixtures of symmetric, log-concave distributions with a common mean.

The paper proposes a neural network architecture inspired by Langevin Monte Carlo for sampling from target distributions.

problem Sampling from complex target distributions efficiently.
method A neural network architecture inspired by Langevin Monte Carlo is proposed to map samples from a simple reference distribution to samples from the target.
result The proposed neural network architecture achieves approximation rates in the Wasserstein-2 distance for smooth, log-concave target distributions.

Thompson Sampling bounds for contextual bandits with sub-Gaussian rewards.

problem Improving the performance of Thompson Sampling in contextual bandits with sub-Gaussian rewards.
method Proved comprehensive bounds on Thompson Sampling expected cumulative regret based on mutual information and lifted information ratio for sub-Gaussian rewards.
result Explicit regret bounds for various contextual bandit scenarios.

In this paper, we consider low rank matrix estimation using either matrix-version Dantzig Selector A^λd\hat{A}_λ^d or matrix-version LASSO estimator A^λL\hat{A}_λ^L. We consider sub-Gaussian measurements, i.e.i.e., the measurements X1,,XnRm×mX_1,\ldots,X_n\in\mathbb{R}^{m\times m} have i.i.d.i.i.d. sub-Gaussian entries. Suppose $\textrm…

2014-03-25abs ↗pdf ↗

Nonparametric Thompson Sampling achieves optimal regret for risk-averse bandits with sub-Gaussian rewards.

problem Optimizing risk-averse bandit problems with sub-Gaussian rewards.
method Anchor-free nonparametric Thompson Sampling algorithm ρextNPTSSGρ ext{-}NPTS_{\mathrm{SG}}.
result Achieves regret matching the instance-dependent lower bound to leading order in logn\log n.

The paper proves a regret bound for a sub-Gaussian mixture on unbounded data.

problem Tackles the challenge of achieving regret bounds for sub-Gaussian mixtures on unbounded data.
method Uses path-wise (deterministic) regret bounds and a cumulative variance process to derive the bound.
result Shows that on a specific event, the regret is eventually bounded by ln(ln V_T).

We study the problem of estimating the mean of a random vector XX given a sample of NN independent, identically distributed points. We introduce a new estimator that achieves a purely sub-Gaussian performance under the only condition that the second moment of XX exists. The estimator is based on a novel concept of a…

2017-02-01abs ↗pdf ↗

We study the algorithmic problem of estimating the mean of heavy-tailed random vector in Rd\mathbb{R}^d, given nn i.i.d. samples. The goal is to design an efficient estimator that attains the optimal sub-gaussian error bound, only assuming that the random vector has bounded mean and covariance. Polynomial-time solutio…

2019-08-13abs ↗pdf ↗

Paper establishes universal lower bounds and optimal rates for clustering sub-exponential mixture models.

problem Achieving optimal error rates in clustering sub-exponential mixture models.
method Establishes universal lower bounds and demonstrates iterative algorithms' optimality in sub-exponential mixture models.
result Iterative algorithms achieve the universal lower bound in sub-exponential mixture models.