arXiv Machine Learning

Optimal Last-Iterate Bounds for Nonexpansive Stochastic Approximation

arXiv Machine Learning
Aug 10

A proximal subgradient method for nonconvex stochastic optimization under the Kurdyka-{\L}ojasiewicz condition

arXiv:2608. 05460v1 Announce Type: cross Abstract: This work introduces a proximal stochastic subgradient method for minimizing the sum of an expected cost, whose integrand is potentially nonsmooth and nonconvex, and a lower semicontinuous, prox-bounded function.

By Felipe Atenas, Alejandro Jofr\'e, Pedro P\'erez-Aros, David Torregrosa-Bel\'en
arXiv Machine Learning
Jul 13

Solving Stochastic Fixed-Point Equations with High Probability

arXiv:2607. 09097v1 Announce Type: cross Abstract: We study stochastic fixed-point equations $\mathbf{T}(\mathbf{x}) = \mathbf{x}$ over normed spaces $(\mathcal{E}, \|\cdot\|)$, where the operator $\mathbf{T}$ is nonexpansive or contractive and is accessed only through unbiased stochastic evaluations with bounded second central moment.

By Jelena Diakonikolas
arXiv Machine Learning
Jul 1

Random Reshuffling Dominates Stochastic Gradient Descent

arXiv:2606. 32005v1 Announce Type: cross Abstract: Stochastic Gradient Descent ($\textsf{SGD}$) is one of the most classical optimization algorithms with favorable theoretical guarantees, yet the practical implementation of $\textsf{SGD}$ differs subtly from its well-known form and is often referred to as Shuffling Stochastic Gradient Descent ($\textsf{Shuffling SGD}$).

By Zijian Liu
arXiv Machine Learning
Jul 21

Concentration and Mean-Square Bounds for Contractive Stochastic Approximation: A Unified Elementary Approach

arXiv:2607. 17595v1 Announce Type: new Abstract: We establish mean-square and concentration bounds for stochastic approximation (SA) with arbitrary norm contractive mappings, under a multiplicative noise model where the noise may scale affinely with the norm of the iterates, and the iterates are potentially unbounded.

By Siddharth Chandak