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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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224447671894 · Jun 202019922001200920172026
48 results for near linear time

In this work, we propose a robust approach to design distributed controllers for unknown-but-sparse linear and time-invariant systems. By leveraging modern techniques in distributed controller synthesis and structured linear inverse problems as applied to system identification, we show that near-optimal distributed con…

2019-09-21abs ↗pdf ↗

Near-optimal algorithms for mean estimation and linear regression with Gaussian covariates and Huber contamination.

problem Gaussian mean estimation and linear regression with Gaussian covariates in the presence of Huber contamination.
method Near-optimal algorithms with optimal error guarantees, achieving sample complexity n=ildeO(d/ε2)n = ilde{O}(d/ε^2) and almost linear runtime.
result First sample near-optimal and almost linear-time algorithms with optimal error guarantees for both problems.

We consider the fundamental learning problem of estimating properties of distributions over large domains. Using a novel piecewise-polynomial approximation technique, we derive the first unified methodology for constructing sample- and time-efficient estimators for all sufficiently smooth, symmetric and non-symmetric, …

2019-11-08abs ↗pdf ↗

New algorithm approximates distributions with near-linear time and optimal sample efficiency.

problem Approximating distributions from samples efficiently and accurately.
method Near-linear-time estimator for distributions using universal polynomial approximation.
result Establishes ct,d=2c_{t,d}=2 for all (t,d)e(1,0)(t,d) e(1,0), achieving optimal approximation.

Compress++ speeds up distribution compression to near-linear time.

problem Accurately summarize a probability distribution using a small number of points efficiently.
method Introduces Compress++, a meta-procedure to speed up any thinning algorithm.
result Achieves n\sqrt{n} points with O(logn/n)\mathcal{O}(\sqrt{\log n/n}) integration error in O(nlog3n)\mathcal{O}(n \log^3 n) time and O(nlog2n)\mathcal{O}( \sqrt{n} \log^2 n ) space.

Improved efficient robust regression with near-linear time and subquadratic samples.

problem Robust linear regression with unknown covariance matrix under Gaussian covariates.
method Near-linear time algorithm using subquadratic samples, complemented by SQ and polynomial lower bounds.
result Achieves prediction error O(εκ)O(\sqrt{εκ}) for εκ1εκ\lesssim 1, improving over prior works.

New algorithm trains neural networks in near-linear time, overcoming slow convergence issues.

problem Slow convergence and computational overhead in training deep neural networks.
method Reformulates Gauss-Newton iteration as an ℓ2-regression problem and uses Fast-JL dimension reduction.
result Achieves an O(mn)-time algorithm for training ReLU networks, near-linear in dimension.

Many important applications, including signal reconstruction, parameter estimation, and signal processing in a compressed domain, rely on a low-dimensional representation of the dataset that preserves {\em all} pairwise distances between the data points and leverages the inherent geometric structure that is typically p…

2016-09-17abs ↗pdf ↗

LinMED is a new linear bandit algorithm with near-optimal regret bound.

problem Optimizing decision-making in linear bandit problems with sub-Gaussian distributions.
method LinMED is a randomized linear bandit algorithm with closed-form arm sampling probabilities.
result LinMED achieves a near-optimal regret bound of dnd\sqrt{n} up to logarithmic factors.

Analyzes Hessian spectrum for neural networks near optimal learning.

problem Understanding learning dynamics near optimal points in neural networks.
method Characterizes Hessian eigenspectrum for teacher-student problems, using analytical and numerical methods.
result The rank of the Hessian matrix determines effective number of parameters for non-linear networks.

Near-logarithmic regret per switch achieved for mixable/exp-concave losses.

problem Online optimization of mixable loss functions with dynamic environments.
method Online mixture framework using static solvers and hyper-expert creations.
result Near-logarithmic regret per switch with sub-polynomial complexity.

This paper develops a fast algorithm for solving nonlinear PDEs using sparse Cholesky factorization.

problem Efficiently solving nonlinear PDEs with Gaussian processes and kernel methods.
method Sparse Cholesky factorization for near-linear complexity.
result Near-linear complexity algorithm for working with kernel matrices of nonlinear PDEs.

Grokking occurs in simple binary logistic classification near linear separability and noise.

problem Delayed generalization in binary logistic classification.
method Analytical and empirical insights into gradient descent dynamics near critical points.
result Logistic regression exhibits grokking when training data is nearly linearly separable from the origin with strong noise.

Efficiently simulates the Heston model with large time steps using a novel method.

problem Challenges in simulating the Heston model with large time steps.
method Implicit integrated variance scheme exploiting the near-linear nature between stochastic driver and conditional integrated variance process.
result Achieves near-exact accuracy with coarse discretizations, efficient for large time steps.

We present an efficient and practical algorithm for the online prediction of discrete-time linear dynamical systems with a symmetric transition matrix. We circumvent the non-convex optimization problem using improper learning: carefully overparameterize the class of LDSs by a polylogarithmic factor, in exchange for con…

2017-11-02abs ↗pdf ↗

New algorithms for differentially private optimization in convex and non-convex settings with near-optimal rates.

problem Differentially private optimization in convex and non-convex settings.
method Developed algorithms for convex and non-convex settings with near-optimal excess population risk.
result Achieved near-optimal rates in near-linear time for convex settings and nearly dimension independent rates for non-convex settings.

In this paper, we establish a framework for the analysis of linear parabolic equations on conical surfaces and use them to study the conical Ricci flow. In particular, we prove the long time existence of the conical Ricci flow for general cone angle and show that this solution has the optimal regularity, namely, the ti…

2016-05-28abs ↗pdf ↗

New method speeds up NIR spectroscopy calibration by 400x.

problem Efficient preprocessing selection in NIR spectroscopy.
method Operator-adaptive PLS and Ridge regression.
result Significant reduction in fitting time with comparable prediction quality.

LightOn OPUs accelerate randomized numerical linear algebra, reducing computational costs.

problem Computational bottleneck in randomization step for large-scale linear algebra.
method Near constant-time linear random projections from LightOn OPUs.
result Significant acceleration of RandNLA algorithms with negligible precision loss.

Paper proposes FedQ-Advantage for federated Q-learning with near-optimal regret and low communication cost.

problem Near-optimal federated Q-learning with low communication cost.
method Reference-advantage decomposition for variance reduction, synchronization between agents and server, policy update.
result Achieves almost optimal regret and near-linear regret speedup compared to single-agent learning.

Study cost-driven state representation learning for control from partial observations.

problem Learning state representation for control from partial and high-dimensional observations.
method Cost-driven state representation learning via predicting cumulative costs.
result Established finite-sample guarantees for near-optimal representation and controller.

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 ↗

New algorithms for model selection in linear bandits adapt to instance complexity.

problem Adapting to the instance-dependent complexity of the true model in linear bandits.
method Design of algorithms in fixed confidence and fixed budget settings, leveraging experimental design and selection-validation procedures.
result Near instance optimal guarantees for model selection in linear bandits.

Direct proof shows adaptive gradient descent converges near-linearly for convex functions.

problem Proving near-linear convergence of adaptive gradient descent for convex functions.
method Direct Lyapunov-based argument for convex functions with unique minimizer.
result Direct proof of near-linear convergence for convex functions.

New approach achieves optimal rates for differentially private stochastic convex optimization with heavy-tailed gradients.

problem Differentially private stochastic convex optimization with heavy-tailed gradients.
method Reduction-based approach to achieve optimal rates.
result Achieved optimal rates up to logarithmic factors, nearly matching a lower bound.

Designs a single policy for collecting data to train near-optimal policies.

problem Engineering overhead in deploying minimax procedures for stochastic linear contextual bandits.
method Designs a single stochastic policy to collect data from which a near-optimal policy can be extracted.
result The designed policy can collect data from which a near-optimal policy can be extracted.