Linear Speedup In Saddle-Point Escape For Decentralized Non-Convex Optimization
Under appropriate cooperation protocols and parameter choices, fully decentralized solutions for stochastic optimization have been shown to match the performance of centralized solutions and result in linear speedup (in the number of agents) relative to noncooperative approaches in the strongly-convex setting. More recently, these results have been extended to the pursuit of first-order stationary points in non-convex environments. In this work, we examine in detail the dependence of second-order convergence guarantees on the spectral properties of the combination policy for non-convex multi agent optimization. We establish linear speedup in saddle-point escape time in the number of agents for symmetric combination policies and study the potential for further improvement by employing asymmetric combination weights. The results imply that a linear speedup can be expected in the pursuit of second-order stationary points, which exclude local maxima as well as strict saddle-points and correspond to local or even global minima in many important learning settings.
WOS:000615970408172
2020-01-01
New York
978-1-5090-6631-5
International Conference on Acoustics Speech and Signal Processing ICASSP
8589
8593
REVIEWED
EPFL
| Event name | Event place | Event date |
Barcelona, SPAIN | May 04-08, 2020 | |