Title
Momentum-Based Variance Reduction in Non-Convex SGD.
Abstract
Variance reduction has emerged in recent years as a strong competitor to stochastic gradient descent in non-convex problems, providing the first algorithms to improve upon the converge rate of stochastic gradient descent for finding first-order critical points. However, variance reduction techniques typically require carefully tuned learning rates and willingness to use excessively large "mega-batches" in order to achieve their improved results. We present a new algorithm, STORM, that does not require any batches and makes use of adaptive learning rates, enabling simpler implementation and less hyperparameter tuning. Our technique for removing the batches uses a variant of momentum to achieve variance reduction in non-convex optimization. On smooth losses F, STORM finds a point x with E{vertical bar vertical bar del F(x)vertical bar vertical bar] <= O(1 / root T + sigma(1/3) / T-1/3) in T iterations with sigma(2) variance in the gradients, matching the optimal rate and without requiring knowledge of sigma.
Year
Venue
Keywords
2019
ADVANCES IN NEURAL INFORMATION PROCESSING SYSTEMS 32 (NIPS 2019)
convex optimization,nonconvex optimization,variance reduction,convex optimisation
Field
DocType
Volume
Applied mathematics,Stochastic gradient descent,Mathematical optimization,Nabla symbol,Hyperparameter,Regular polygon,Momentum,Critical point (mathematics),Variance reduction,Adaptive learning,Mathematics
Journal
32
ISSN
Citations 
PageRank 
1049-5258
0
0.34
References 
Authors
0
2
Name
Order
Citations
PageRank
Cutkosky, Ashok11410.02
Francesco Orabona288151.44