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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.

169,051 papers · 148 categories

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265177102 · Jun 202019922001200920172026
48 results for non-convex thresholding

Multi-task feature learning aims to identity the shared features among tasks to improve generalization. It has been shown that by minimizing non-convex learning models, a better solution than the convex alternatives can be obtained. Therefore, a non-convex model based on the capped-1,1\ell_{1},\ell_{1} regularization wa…

2014-06-16abs ↗pdf ↗

Online SGD achieves consistent estimation in high-dimensional non-convex inference tasks.

problem Consistent estimation in high-dimensional non-convex optimization problems.
method Online stochastic gradient descent (SGD) on non-convex losses.
result Nearly sharp thresholds for sample complexity in high-dimensional settings.

Study accelerates optimization methods in non-convex problems, but doesn't improve the algorithm's performance.

problem Understanding the behavior of momentum-based acceleration methods in non-convex, high-dimensional landscapes.
method Used dynamical mean field theory to describe the average dynamics of heavy-ball momentum and Nesterov acceleration in a non-convex model.
result Accelerated dynamics but did not improve the algorithm's performance with respect to gradient descent.

CDP reduces point cloud dimensions by preserving detour-induced local non-convexity.

problem Preserving local non-convexity in point cloud dimensionality reduction.
method CDP builds a k-NN graph, identifies admissible pairs, aggregates normalized directions, and uses top-k eigenvectors for projection.
result CDP provides verifiable guarantees on post-projection distortion and direction energy.

Dash selects dynamic pseudo labels from unlabeled data for semi-supervised learning.

problem Efficiently using unlabeled data in semi-supervised learning while avoiding incorrect pseudo labels.
method Dynamic thresholding to select a subset of unlabeled examples for training.
result Dash achieves theoretical convergence and outperforms state-of-the-art methods empirically.

We study --both in theory and practice-- the use of momentum motions in classic iterative hard thresholding (IHT) methods. By simply modifying plain IHT, we investigate its convergence behavior on convex optimization criteria with non-convex constraints, under standard assumptions. In diverse scenaria, we observe that …

2017-12-26abs ↗pdf ↗

Efficient distributed learning with Byzantine-resilient thresholding and error feedback.

problem Byzantine-resilient distributed learning with communication efficiency.
method Simple thresholding for Byzantine mitigation, compressed gradients and norms for aggregation, error feedback.
result Statistical error rate matches Yin et al.~\cite{dong} but with simpler schemes, and improved convergence with error feedback.

New bounds found for optimizing non-convex functions with noisy data.

problem Limits of first-order stochastic optimization in non-convex settings.
method Divergence decomposition to construct challenging subclasses.
result Sharp lower bounds on noisy gradient queries for various non-convex classes.

Paper analyzes robust matrix completion with efficient nonconvex method and leave-one-out analysis.

problem Robust matrix completion with sparse noise.
method Alternates between projected gradient step for low-rank and thresholding step for sparse noise.
result Achieves linear convergence for general thresholding functions.

New method for robust regression with near-optimal performance even with high corruption rates.

problem Robust linear regression with response variable corruptions.
method Adaptive hard thresholding for consistent estimation.
result Near-optimal consistent estimation of the true regression vector with 1o(1)1-o(1) fraction of corruptions.

Paper proposes GPM for simultaneous community detection and group synchronization.

problem Simultaneous community detection and group synchronization in networks.
method Generalized Power Method (GPM) for non-convex optimization.
result GPM achieves exact recovery in O(nlog2n)O(n\log^2n) time, outperforming SDP.

A new algorithm, Regular Tree Search, tackles non-convex simulation optimization problems.

problem Non-convex objective functions in simulation optimization.
method Integrates adaptive sampling with recursive partitioning of the search space.
result Proves global convergence and reliably identifies the global optimum.

This paper is concerned with the hard thresholding operator which sets all but the kk largest absolute elements of a vector to zero. We establish a {\em tight} bound to quantitatively characterize the deviation of the thresholded solution from a given signal. Our theoretical result is universal in the sense that it ho…

2016-05-05abs ↗pdf ↗

Significant attention has been given to minimizing a penalized least squares criterion for estimating sparse solutions to large linear systems of equations. The penalty is responsible for inducing sparsity and the natural choice is the so-called l0l_0 norm. In this paper we develop a Momentumized Iterative Shrinkage Th…

2014-09-25abs ↗pdf ↗

New algorithm robustly optimizes data streams with heavy-tailed or infinite variance samples.

problem Optimizing data streams with heavy-tailed or infinite variance samples.
method Gradient quantile clipping for SGD, leveraging Markov chain connections.
result Algorithm converges to a concentrated distribution with high probability bounds.

Paper studies early-stopped mirror descent for noisy sparse phase retrieval.

problem Recovering a sparse signal from noisy quadratic measurements.
method Early-stopped mirror descent with hyperbolic entropy mirror map.
result Achieves nearly minimax-optimal rate of convergence for kk-sparse signals.

Gradient-flow helps find good minima in complex models.

problem Understanding why gradient-based algorithms work in non-convex optimization.
method Kac-Rice analysis and gradient-flow from statistical physics.
result Gradient-flow finds good global minima in the presence of many spurious local minima.

This work analyzes how overparameterization aids GANs in reaching global saddle points.

problem Understanding the role of overparameterization in GANs for convergence to global saddle points.
method Theoretical and empirical analysis of overparameterized GANs with various architectures and datasets.
result GDA converges to a global saddle point in overparameterized GANs with certain assumptions.

In this paper, we propose a general framework for sparse and low-rank tensor estimation from cubic sketchings. A two-stage non-convex implementation is developed based on sparse tensor decomposition and thresholded gradient descent, which ensures exact recovery in the noiseless case and stable recovery in the noisy cas…

2018-01-29abs ↗pdf ↗

Continuous-time mirror descent solves sparse phase retrieval efficiently.

problem Recovering sparse signals from magnitude-only measurements.
method Continuous-time mirror descent applied to unconstrained empirical risk minimization problem.
result Mirror descent recovers kk-sparse vectors with minimum non-zero entry order of x2/k\| \mathbf{x}^\star \|_2/\sqrt{k} from k2k^2 Gaussian measurements.

A new ODE model explains gradient descent dynamics near edge of stability.

problem Understanding gradient-based training over non-convex landscapes.
method Rod Flow, a new ODE approximation of GD dynamics.
result Rod Flow accurately predicts critical sharpness threshold and self-stabilization in quartic potentials.

Averaged Gradient Descent improves performance in rough landscapes.

problem Minimizing strongly non-convex functions in high-dimensional estimation problems.
method Empirical average of gradients over random positions in parameter space.
result Averaged Gradient Descent outperforms existing methods in tensor PCA.

Paper proposes a new algorithm combining gradient descent and Langevin dynamics.

problem Gradient descent can get stuck in local minima, while Langevin dynamics can explore but is slow.
method Replica exchange mechanism swaps positions if Langevin yields a lower objective function.
result New algorithm converges to global minimum linearly with high probability.

This paper improves 3D pose recovery from 2D images using non-convex regularization.

problem 3D object pose recovery from 2D images.
method Proposes non-convex regularization with leaky capped ℓ1-norm (LCNR) and multi-stage optimization.
result Theoretical analysis shows estimation error decreases with optimization stages.

The paper analyzes how good initial guesses affect the amount of data needed for low-rank matrix recovery.

problem Theoretical guarantee of local optimization algorithms requires excessive data to prevent spurious local minima.
method Quantifies the relationship between initial guess quality and sample complexity using restricted isometry constant.
result A linear improvement in initial guess quality leads to a constant factor improvement in sample complexity.

New methods solve graph sparsity optimization problems faster.

problem Complex graph sparsity optimization problems in disease outbreak monitoring and social network analysis.
method Stochastic variance-reduced gradient-based methods GraphSVRG-IHT and GraphSCSG-IHT.
result Our methods achieve linear convergence speed.

The paper analyzes trace regression with low-rank matrices under various regularization methods.

problem Estimating low-rank matrices with near-optimal error bounds under unknown regularization parameters.
method General spikiness notion, restricted strong convexity of sampling operator, cross-validation for parameter selection.
result Cross-validated estimators select near-optimal penalty parameters and outperform theory-inspired approaches.

New insights on robust learning under strong noise models.

problem Challenging label-noise models in robust learning.
method Extending statistical query framework to more general noise models and using evolutionary algorithms.
result First polynomial time algorithm for learning linear threshold functions with arbitrarily small excess error in presence of Tsybakov noise.

First order methods can take extremely long to find global minima of non-convex functions.

problem Finding global minimizers of non-convex functions.
method Designing a family of non-convex functions and using statistical lower bounds for parameter estimation.
result First order methods can take exponential time to converge to a global minimizer.

New algorithm improves convergence for non-convex problems with boundaries.

problem Optimizing non-convex problems with constraints.
method Reflected Gradient Langevin Dynamics with probabilistic representation.
result Promising convergence rates, faster than existing methods.