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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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136271407542 · Jun 202019922001200920172026
48 results for Strong minimax lower bounds

New methods solve complex optimization problems without strong convexity assumptions.

problem Complex bilevel optimization problems with minimax lower-level structures.
method Penalty-based first-order methods for bilevel minimax optimization.
result Achieves εε-KKT point with improved oracle complexity.

Paper sets fundamental limits for distributed covariance estimation with constrained communication.

problem Estimating high-dimensional covariance matrices in a feature-split setting with limited communication.
method Developed a Conditional Strong Data Processing Inequality (C-SDPI) to establish minimax lower bounds and an optimal estimation protocol.
result Achieved nearly optimal estimation protocol with sample and communication requirements matching lower bounds up to logarithmic factors.

Paper solves minimax optimization gap with near-optimal algorithms.

problem Designing efficient algorithms for smooth and strongly-convex-strongly-concave minimax problems.
method Accelerated proximal point method and accelerated solver for minimax proximal steps.
result First algorithm with gradient complexity matching the lower bound up to logarithmic factors.

Study minimax rates for binary classifier estimation with margin conditions.

problem Estimating binary classifiers with geometric margin conditions.
method Derive lower bounds for worst-case learning rates over various function classes.
result Identify optimal rates close to O(n1)\mathcal{O}(n^{-1}) for different function classes.

Study minimax linear regression under quantile risk, improving existing bounds and providing new results.

problem Designing minimax procedures in linear regression under quantile risk.
method Analyzes realizable setting with Gaussian noise, extends to all p-th power error functions, develops new lower and upper bounds.
result Proves minimaxity of a variant of the min-max regression procedure for all p-th power error functions.

Develops high-probability minimax quantile bounds for statistical problems.

problem Statistical procedures often lose information about tail behavior when reduced to expectations.
method Introduces minimax quantiles, develops high-probability variants of minimax methods, and converts risk lower bounds to quantile lower bounds.
result Obtains high-probability minimax quantile lower bounds for various statistical problems.

New research sets the minimax lower bound for KSD estimation at sqrt(n).

problem Estimating goodness-of-fit using Kernel Stein Discrepancy (KSD) on high-dimensional spaces.
method Two complementary results proving the minimax lower bound of KSD estimation.
result The minimax lower bound of KSD estimation is n^(-1/2), indicating exponential difficulty with dimensionality.

Exact minimax risk derived for linear prediction with sample covariance analysis.

problem Understanding the minimax risk in linear prediction under various covariate distributions.
method Exact minimax risk analysis, leveraging statistical leverage scores and PAC-Bayes techniques.
result The minimax risk is of order d/(nd+1)d/(n-d+1) for any covariate distribution, nearly matching the risk for Gaussian design.

Estimates sparse topic models with improved efficiency and adaptability.

problem Estimating sparse topic models with unknown sparsity and number of topics.
method Proposes a new algorithm for efficient estimation of sparse topic models with non-negative matrices.
result Upper bound matches minimax lower bound, demonstrating optimal performance.

Study on QQ-function estimation for continuous state-action MDPs, deriving rates and conditions.

problem Estimating QQ-function in off-policy evaluation for continuous state-action Markov decision processes.
method Reformulated as nonparametric instrumental variables (NPIV) problem, derived minimax lower bounds, proposed sieve two-stage least squares estimator.
result First minimax lower bounds for QQ-function and its derivatives in sup-norm and L2L^2-norm, same as classical nonparametric regression.

Kernel method improves instrumental variable regression rates.

problem Nonparametric instrumental variable regression with weak instruments.
method Kernel-based two-stage least-squares method, strong L2L_2 convergence analysis.
result Minimax optimal rates for instrumental regression under standard assumptions.

New research shows that binary classification can be done with noisy data, but only if there are clean samples available.

problem Learning binary classification with instance and label dependent label noise.
method Theoretical analysis and empirical risk minimization.
result Empirical risk minimization achieves the optimal excess risk bound without additional assumptions.

Novel methods for accelerating optimization in complex bilevel and minimax problems.

problem Optimization challenges in bilevel and minimax problems, especially when strong convexity assumptions are not met.
method Accelerated fully first-order methods for Bilevel Optimization (BLO) and Minimax Optimization (NCSC).
result State-of-the-art complexity for finding approximate second-order stationary points in BLO and NCSC.

New method generates private synthetic data with optimal utility for smooth queries.

problem Achieving strong utility guarantees for meaningful downstream analysis of sensitive datasets.
method Proposes a polynomial-time algorithm for generating (ε,δ)(\varepsilon,δ)-differentially private synthetic data with minimax optimal error rates for smooth queries.
result Achieves a minimax error rate of Ok,d(nmin{1,kd})O_{k,d}(n^{-\min \{1, \frac{k}{d}\}}) for kk-smooth queries, up to a log(n)\log(n) factor.

Study tackles contamination and heterogeneity in multi-task learning, improving robustness and personalization.

problem Challenges in integrating related tasks due to contamination and heterogeneity.
method Proposes a filtering-based robust multi-task gradient descent method to estimate global and clean task-specific minimizers.
result Demonstrates improved robustness and personalization compared to existing methods.

Study finds optimal regret bound for multi-armed bandit problem with expert advice.

problem Optimizing decision-making in a multi-armed bandit problem with expert advice.
method Proved a tight lower bound matching the upper bound of Kale (2014) for minimax expected regret.
result The minimax optimal expected regret is Θ(√(T K log (N/K))) for the problem.

Dictionary learning is the problem of estimating the collection of atomic elements that provide a sparse representation of measured/collected signals or data. This paper finds fundamental limits on the sample complexity of estimating dictionaries for tensor data by proving a lower bound on the minimax risk. This lower …

2016-05-17abs ↗pdf ↗

Sparse covariance estimation in the vertical-split model achieves exponential improvement over dense estimates.

problem Minimax estimation error for distributed covariance matrix estimation in the vertical-split setting.
method Elementwise ss-sparsity is shown to reduce communication and sample complexity.
result Minimax lower bounds for 11-sparse cross-covariance estimation are established.

The paper tackles deep learning from dependent data, achieving optimal performance.

problem Deep learning from strongly mixing observations, especially with regularization and optimality.
method Sparse-penalized regularization for deep neural networks, oracle inequality for expected excess risk.
result Deep neural network estimator achieves minimax optimal rate for nonparametric autoregression.

Unified framework for corruption-robust linear bandits with optimal gap-dependent misspecification bounds.

problem Effective learning in linear bandits with corrupted rewards across different corruption models.
method Unified framework for analyzing strong and weak corruption, connection to gap-dependent misspecification, and specialized algorithm.
result Optimal bounds for gap-dependent misspecification in linear bandits.

Study minimax regret in sequential probability assignment with and without side information.

problem Minimax regret analysis in sequential probability assignment.
method Upper and lower bounds on minimax regret using square-root entropy.
result Lower bound matches upper bound for Donsker classes, up to log factors.

Rejection Sampling is a fundamental Monte-Carlo method. It is used to sample from distributions admitting a probability density function which can be evaluated exactly at any given point, albeit at a high computational cost. However, without proper tuning, this technique implies a high rejection rate. Several methods h…

2018-10-22abs ↗pdf ↗

Paper explores generalization of minimax learners, proposing a new metric.

problem Understanding how minimax learners perform on unseen data.
method Proposes a new metric, the primal gap, to study generalization of minimax learners.
result Derives generalization error bounds for the primal gap in nonconvex-concave settings.

The study establishes minimax bounds for estimating operators from noisy samples.

problem Estimating unknown operators between Hilbert spaces from noisy data.
method Developed a minimax theory for uniformly bounded Lipschitz operators, proving lower and upper bounds.
result Sharp characterizations of minimax risk for generic Lipschitz operators, showing a curse of sample complexity.

Paper explores fair classification with bounded disparity using finite datasets.

problem Ensuring fairness in binary classification with protected groups.
method Minimax optimal approach with fairness constraints and demographic disparity control.
result Proposes FairBayes-DDP+ method that achieves minimax lower bound on fairness-aware excess risk.

Transductive learning considers a training set of mm labeled samples and a test set of uu unlabeled samples, with the goal of best labeling that particular test set. Conversely, inductive learning considers a training set of mm labeled samples drawn iid from P(X,Y)P(X,Y), with the goal of best labeling any future sample…

2016-02-09abs ↗pdf ↗

We consider a sequential learning problem with Gaussian payoffs and side information: after selecting an action ii, the learner receives information about the payoff of every action jj in the form of Gaussian observations whose mean is the same as the mean payoff, but the variance depends on the pair (i,j)(i,j) (and may…

2015-10-27abs ↗pdf ↗

Detecting a planted submatrix in random matrices with non-asymptotic methods.

problem Detecting a planted submatrix in random matrices with non-zero entries.
method Established minimax lower bounds and derived optimal tests for distinguishing the null and alternative hypotheses.
result Non-asymptotic upper and lower bounds match for any configuration of matrix dimensions.

The cost-sensitive classification problem plays a crucial role in mission-critical machine learning applications, and differs with traditional classification by taking the misclassification costs into consideration. Although being studied extensively in the literature, the fundamental limits of this problem are still n…

2018-05-20abs ↗pdf ↗

Spectral algorithms on manifolds using diffusion kernels improve convergence rates.

problem The limitations of existing spectral algorithms in RKHSs for data on manifolds.
method Integrating manifold structure into spectral algorithms using heat kernel diffusion spaces.
result Spectral algorithms converge to the target function and its derivatives in a strong sense, with rates dependent on manifold intrinsic dimension.

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 ↗

An important class of distance metrics proposed for training generative adversarial networks (GANs) is the integral probability metric (IPM), in which the neural net distance captures the practical GAN training via two neural networks. This paper investigates the minimax estimation problem of the neural net distance ba…

2018-11-02abs ↗pdf ↗