Title
Convergence Analysis of Proximal Gradient with Momentum for Nonconvex Optimization.
Abstract
In many modern machine learning applications, structures of underlying mathematical models often yield nonconvex optimization problems. Due to the intractability of nonconvexity, there is a rising need to develop efficient methods for solving general nonconvex problems with certain performance guarantee. In this work, we investigate the accelerated proximal gradient method for nonconvex programming (APGnc). The method compares between a usual proximal gradient step and a linear extrapolation step, and accepts the one that has a lower function value to achieve a monotonic decrease. In specific, under a general nonsmooth and nonconvex setting, we provide a rigorous argument to show that the limit points of the sequence generated by APGnc are critical points of the objective function. Then, by exploiting the Kurdyka-{L}ojasiewicz (KL) property for a broad class of functions, we establish the linear and sub-linear convergence rates of the function value sequence generated by APGnc. We further propose a stochastic variance reduced APGnc (SVRG-APGnc), and establish its linear convergence under a special case of the KL property. We also extend the analysis to the inexact version of these methods and develop an adaptive momentum strategy that improves the numerical performance.
Year
Venue
DocType
2017
ICML
Conference
Volume
Citations 
PageRank 
abs/1705.04925
7
0.48
References 
Authors
9
4
Name
Order
Citations
PageRank
qunwei li1686.42
Yi Zhou26517.55
Yingbin Liang31646147.64
Pramod K. Varshney46689594.61