Stochastic policy gradient methods: Improved sample complexity for fisher-non-degenerate policies

I Fatkhullin, A Barakat, A Kireeva… - … Conference on Machine …, 2023 - proceedings.mlr.press
Recently, the impressive empirical success of policy gradient (PG) methods has catalyzed
the development of their theoretical foundations. Despite the huge efforts directed at the …

Momentum and stochastic momentum for stochastic gradient, newton, proximal point and subspace descent methods

N Loizou, P Richtárik - Computational Optimization and Applications, 2020 - Springer
In this paper we study several classes of stochastic optimization algorithms enriched with
heavy ball momentum. Among the methods studied are: stochastic gradient descent …

Momentum improves normalized sgd

A Cutkosky, H Mehta - International conference on machine …, 2020 - proceedings.mlr.press
We provide an improved analysis of normalized SGD showing that adding momentum
provably removes the need for large batch sizes on non-convex objectives. Then, we …

High-probability bounds for non-convex stochastic optimization with heavy tails

A Cutkosky, H Mehta - Advances in Neural Information …, 2021 - proceedings.neurips.cc
We consider non-convex stochastic optimization using first-order algorithms for which the
gradient estimates may have heavy tails. We show that a combination of gradient clip** …

The marginal value of momentum for small learning rate sgd

R Wang, S Malladi, T Wang, K Lyu, Z Li - arxiv preprint arxiv:2307.15196, 2023 - arxiv.org
Momentum is known to accelerate the convergence of gradient descent in strongly convex
settings without stochastic gradient noise. In stochastic optimization, such as training neural …

Momentum ensures convergence of signsgd under weaker assumptions

T Sun, Q Wang, D Li, B Wang - International Conference on …, 2023 - proceedings.mlr.press
Abstract Sign Stochastic Gradient Descent (signSGD) is a communication-efficient stochastic
algorithm that only uses the sign information of the stochastic gradient to update the model's …

Meta learning on a sequence of imbalanced domains with difficulty awareness

Z Wang, T Duan, L Fang, Q Suo… - Proceedings of the …, 2021 - openaccess.thecvf.com
Recognizing new objects by learning from a few labeled examples in an evolving
environment is crucial to obtain excellent generalization ability for real-world machine …

Online optimization over riemannian manifolds

X Wang, Z Tu, Y Hong, Y Wu, G Shi - Journal of Machine Learning …, 2023 - jmlr.org
Online optimization has witnessed a massive surge of research attention in recent years. In
this paper, we propose online gradient descent and online bandit algorithms over …

Riemannian optimistic algorithms

X Wang, D Yuan, Y Hong, Z Hu, L Wang… - arxiv preprint arxiv …, 2023 - arxiv.org
In this paper, we consider Riemannian online convex optimization with dynamic regret. First,
we propose two novel algorithms, namely the Riemannian Online Optimistic Gradient …

Root-sgd: Sharp nonasymptotics and asymptotic efficiency in a single algorithm

CJ Li, W Mou, M Wainwright… - Conference on Learning …, 2022 - proceedings.mlr.press
We study the problem of solving strongly convex and smooth unconstrained optimization
problems using stochastic first-order algorithms. We devise a novel algorithm, referred to …